Abstract

Understanding and controlling defect in two-dimensional materials is important for both linear and nonlinear optoelectronic devices, especially in terms of tuning nonlinear optical absorption. Taking advantage of an atomic defect formed easily by smaller size, molybdenum disulfide nanosheet is prepared successfully with a different size by gradient centrifugation. Interestingly, size-dependent sulfur vacancies are observed by high-resolution X-ray photoelectron spectroscopy, atomic force microscopy, and transmission electron microscopy. The defect effect on nonlinear absorption is investigated by Z-scan measurement at the wavelength of 800 nm. The results suggest the transition from saturable absorption to reverse saturable absorption can be observed in both dispersions and films. First principle calculations suggest that sulfur vacancies act as the trap state to capture the excited electrons. Moreover, an energy-level model with the trap state is put forward to explain the role of the sulfur vacancy defect in nonlinear optical absorption. The results suggest that saturable absorption and reverse saturable absorption originate from the competition between the excited, defect state and ground state absorption. Our finding provides a way to tune the nonlinear optical performance of optoelectronic devices by defect engineering.

© 2020 Chinese Laser Press

1. INTRODUCTION

Unavoidable defects in the growth process of two-dimensional (2D) materials can dramatically affect the performance of the corresponding device. Defect-associated nonradiative recombination will lead to low quantum efficiency (<0.6%) [1], and structure defects will result in lower carrier mobility [2]. Defects can also be a source of merit; for instance, photoluminescence enhancement induced by sulfur (S) vacancy [3] and oxygen bonding at the defect sites [4] in monolayer molybdenum disulfide (MoS2) and catalytic efficiency in hydrogen evolution reaction improved by S vacancies [5] at edge defects [6]. However, the contribution of these defects to the nonlinear optical (NLO) properties, such as saturable absorption (SA) and reverse saturable absorption (RSA), is not completely clear so far. Recently, different defect types, including effective two-photon absorption (TPA) from zinc (Zn) vacancy [7], tunable NLO absorption derived from the concentration of manganese doping [8], and enhanced modulation depth [9] from localized defect states at grain boundaries, have been introduced to improve the performance of nonlinear photonic devices. Actually, these defects act as different trap centers to capture electrons [10], holes [11], or excitons [12,13], which make it crucial to confirm the type of defect-induced localized states in 2D materials.

MoS2 is a typical 2D material to design linear optoelectronic devices due to its excellent optical and electronic properties, including high current on/off ratio (108), high electron mobility (102  cm2·V1·s1) [14], strong catalytic activity [15], and photoluminescence [16,17]. Importantly, a size-dependent few-layer MoS2 can be achieved easily using ultrasonic exfoliation [18] combined with the gradient centrifugation method [19]. On the other hand, nonlinear photonic applications including Q-switching [20], mode-locking [21,22], and an optical limiter [23] have also been designed based on SA and RSA behavior. For example, MoS2 and graphene were reported with stronger SA [24] than those of MoTe2 and MoSe2, while BN exhibited a strong RSA effect [25]. SA and RSA can be interpreted as a transmission increasing and decreasing according to pump intensity, respectively. It is determined by a smaller absorption cross section in excited state compared with that in ground state for SA [20,26]. On the other hand, RSA occurs due to larger absorption cross section in excited state compared with that in ground state. Including SA and RSA, some defects can be introduced to improve optical and electronic properties in MoS2 material. For instance, the defect level of bulk MoS2 can be tuned from 1.08 to 0.08 eV [27] by S vacancies. The S vacancies can easily transform MoS2 into an n-type conductor, whereas the Mo vacancies can be used to transform MoS2 into a p-type conductor [28]. Particularly, these atomic defects are easily formed in small MoS2 nanosheets compared to those in large nanosheets [29]. Interestingly, the changeover from SA to RSA has been observed in MoS2 nanosheet dispersions with size using a picosecond laser [30], which is caused by certain edge defect. However, the defect type-size relationship is yet to be identified as well as its related mechanisms in NLO properties. In addition, the reported nonlinear responses are based on liquid environments, and thus it is hard to avoid thermally induced nonlinear scattering [31]. A femtosecond laser source can avoid this condition due to the slow formation of bubbles from the ultrashort pulse laser [32]. It is also easy to solve the problem and design nonlinear optics-based devices by preparing films [33].

In this work, we first present an effective method to introduce S vacancies in MoS2 by adjusting the nanosheet size. Different nanosheet sizes are obtained through liquid-phase exfoliation by controlling the centrifugation speed, and films with different sizes are fabricated by the vacuum filtration technique. The successful size-separation is identified by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The size-dependent S vacancies are confirmed by Raman spectroscopy and high-resolution X-ray photoelectron spectroscopy (XPS). The influence of S vacancy concentration on NLO properties is studied by a typical Z-scan setup at 800 nm. The changeover from SA to RSA is observed both in films and dispersions. Combined with the S vacancy defect state, which is confirmed by first principle calculations, an energy-level model is carried out based on S vacancy concentration. SA and RSA are strongly related to ground state, excited state, and defect state absorption. This work provides a method to tune nonlinear photonic devices by controlling the defects.

2. RESULTS AND DISCUSSION

A. Methods: MoS2 Nanosheet Dispersion and Film Preparation

A green ethanol-based solvent exfoliation process was used to prepare few-layer MoS2 nanosheets [34]. Initially, we chose 40% ethanol mixed with deionized water for 0.9 g MoS2 in a 300 mL mixed solution. We settled the parameters with 700 W for 3 h using the supersonic machine (Qsonica Q700) to prepare the dispersion. After that, the nanosheet supernatant was acquired with a centrifuge (Centurion Scientific K241) by controlling the rotation speeds with 2000 rpm, 4000 rpm, 6000 rpm, and 8000 rpm for 15 min to remove large nanoparticles. To obtain a larger MoS2 nanosheet, ultrasonic exfoliation with 70 W for 3 h was used and then let the acquired dispersion stand two weeks with 0 rpm. Subsequently, we can prepare the films with almost the same thickness by controlling filtration volume using the vacuum filtration technique.

B. Characterization of MoS2 Dispersions and Films

The MoS2 nanosheet was successfully exfoliated from optical images of MoS2 dispersion and presented in Fig. 1(a). In addition, MoS2 concentration was measured from 0.01 to 0.24 mg/mL. To investigate the relationship between the size and optical bandgap, a Tauc plot derived from UV–Vis spectra of MoS2 dispersions with a different centrifugation speed is given in Fig. 1(b). The result shows that the bandgap of MoS2 dispersions ranged from 1.36 to 1.27 eV with increased centrifugation speed. The size-dependent bandgap is supposed to be induced by S and Mo atom vacancies [2,35].

 

Fig. 1. (a) Concentrations of MoS2 dispersion at different rotation speeds with related optical images inserted. (b) Tauc plot of MoS2 dispersions. (c) Size and height of MoS2 dispersions at different rotation speeds. (d), (g) AFM image and height profile of MoS2 at 2000 rpm. (e), (h) AFM image and height profile of  MoS2 at 4000 rpm. (f), (i) AFM image and height profile of MoS2 at 6000 rpm. The number indicates the different nanosheet.

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To further confirm the successful size-separation of MoS2, the dispersions were dropped respectively on glass substrate and measured by AFM. Figure 1(c) summarizes the average MoS2 nanosheet diameters at a different centrifugation speed, which indicates evidently that the average diameter is 0.60 μm at 0 rpm with a thickness of 15  nm, and the finest average diameter is 0.29 μm at 8000 rpm with a thickness of 6.5  nm. In addition, Figs. 1(d) and 1(g) show the average diameter is 0.52 μm, with a thickness of roughly 8.8 nm at 2000 rpm; the average diameter is 0.35 μm, with a thickness of roughly 7.3 nm at 4000 rpm in Figs. 1(e) and 1(h); the average diameter is 0.32 μm, with a thickness of roughly 6.7 nm at 6000 rpm in Figs. 1(f) and 1(i).

The nanosheet size was also confirmed using TEM as shown in Fig. 2. The maximum flake size is 600 nm at 0 rpm, whereas the minimum nanosheet size is 280  nm at 8000 rpm. In Figs. 2(a)2(e), ultrathin nanosheets can be observed by examining the layer edges. Obviously, the ultrathin nanosheet can be obtained at 8000 rpm with the minimum concentration. These TEM results are consistent with AFM results as shown in Fig. 1(c). Defects are observed at the edge of the nanosheets with high-resolution TEM as presented in Fig. 2(f). The spacing of the nanosheet at 6000 rpm is 6.61±0.01  Å, whereas the interlayer spacing of bulk MoS2 is 6.2  Å. The fringe of the nanosheet edge is not continuous, which can be attributed to the existence of S or Mo vacancies [5,36]. To confirm the defect type in the nanosheet, elemental mapping of S and Mo is presented in Figs. 2(h) and 2(i). At the nanosheet edge, Mo atoms have a higher density compared to S atoms; moreover, the abundant removal of S atoms can be easily observed at the flake edge.

 

Fig. 2. Representative TEM images of MoS2 dispersions at (a) 0, (b) 2000, (c) 4000, (d) 6000, and (e) 8000 rpm. (f) High-resolution TEM image of MoS2 nanosheet at 6000 rpm. (g) TEM image of ultrathin layer of MoS2 defect at 8000 rpm; elemental mapping of (h) Mo (i) S.

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XPS was further applied to confirm the S vacancies by analyzing the S:Mo ratio of MoS2 film in Fig. 3(a). We selected an optimal thickness of 45  nm according to controlled filtration volume. We did not observe evident MoO3 component at 236.3 eV. Therefore, we can ignore the MoO3 in the sample. The shift of binding energy comes from reduced electronegative S neighbors [5,37]. The results agree well with Raman peaks shift in Fig. 3(d), indicating the change of S vacancies. At 0 rpm, the S: Mo ratio is 2.12, which suggests abundant S in the growth process at the beginning. However, with the increase in centrifugation speed, the ratio of S:Mo decreases from 1.67 to 0.80, implying more S vacancy formation. There are two mechanisms that can produce S vacancies. First, a small nanosheet with highly exposed edge terminations [29,38] easily gives rise to the S vacancy defect instead of Mo vacancy in the MoS2 nanosheet due to the low formation energy. Second, ultrasonic exfoliation needs long-time high energies to bombard the MoS2 surface and further produce S vacancies.

 

Fig. 3. (a) High-resolution XPS spectra of MoS2 films. (b) XRD patterns of MoS2 films. (c) Raman spectra of MoS2 films. (d) Raman shift of E2g1 and A1g. (e) UV-Vis absorption spectra of MoS2 films. (f) Tauc plot obtained from UV-Vis absorption spectra of MoS2 films with an increase in centrifugation speed.

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Further XRD experiments are presented in Fig. 3(b), from which three peaks can be observed at 14.37°, 39.53°, and 60.14°, corresponding to the hexagonal MoS2 (0 0 2), (0 0 4), and (0 0 8), respectively. The peaks drastically decrease in intensity, indicating reduced crystallinity with the increase of centrifugation speed due to the increased S vacancies. Similarly, the defects can also be confirmed by the Raman spectra in Fig. 3(c), from which MoS2 peaks can be observed at 383.5 and 408.7  cm1, corresponding to the E2g1 and A1g mode [39], respectively. We have not observed the evident peak at 223  cm1, which is associated with MoO2 [40]. As such, the MoO2 can be ignored in samples. We observed the reduced intensity with the increase of centrifugation speed, which may be due to the reduced crystallinity induced by S vacancies, and which agrees well with the XRD results in Fig. 3(b). The A1g mode indicates out-of-plane S atoms displacement, whereas the E2g1 mode is in-plane displacement from Mo and S atoms. As presented in Fig. 3(d), the E2g1 mode has a red shift from 383.5 to 381.8  cm1 with the increase of centrifugation speed, which can be attributed to the increase in the number of S vacancies in MoS2 [6]. Conversely, the A1g mode shifts from 407.5 to 408.7  cm1 due to the increase in defect density [41]. Through UV-Vis absorption spectra of MoS2 films, A and B exciton peaks are, respectively, observed as shown in Fig. 3(e); the optical bandgaps have the estimation of 1.30  eV by a Tauc plot as shown in Fig. 3(f). This is different with MoS2 dispersions in Fig. 1(b) probably due to multilayer films. The aforementioned characterization results suggest that MoS2 films with a different centrifugation speed have different concentrations of S vacancies.

C. Size-Dependent Nonlinear Absorption of MoS2 Dispersions and Films

In our previous reports, an open aperture Z-scan measurement at the wavelength of 800 nm with a pulse duration of 35 fs and repetition frequency of 1 kHz was equipped. The waist radius was about 30 μm measured by a knife edge method. It was performed to study the NLO property of transition metal dichalcogenides film [34,42]. There is no evident signal from the solution (ethanol) in quartz cuvette at a pulse energy of 0.5 μJ. SA occurs in MoS2 dispersions at 0 rpm according to the dependence of transmittance peak on pulse energy as presented in Fig. 4(a). Alternatively, RSA occurs in MoS2 dispersion at 6000 rpm as shown in Fig. 4(b). Therefore, the influence of nanosheet size on nonlinear absorption was investigated and depicted in Fig. 4(c), in which a smaller transmittance at the focus position (0 mm in Z-scan) can be observed with the increase in centrifugation speed. With the same thickness of 45 nm but different centrifugation speed, the MoS2 film shows a conversion from SA to RSA with the increase in centrifugation speed as presented in Fig. 4(e), and eventually the RSA behavior is observed for MoS2 film at 8000 rpm as shown in Fig. 4(d). However, 75-nm-thick MoS2 films only exhibit SA phenomena, as shown in Fig. 4(f), compared to the 45-nm-thick ones. In our experiments, both SA and RSA exist in the MoS2 dispersions and films. SA can be mainly attributed to the bandgap of multilayer MoS2 being less than 1.55 eV while RSA may be induced by nonlinear scattering, excited state absorption, TPA, and so on. Therefore, the experimental Z-scan results are theoretically analyzed by a nonlinear absorption model including both SA and RSA [30,43,44]. Equation (1) is as follows:

α(I)=α01+(I/Is)+βeffI,
where I denotes the intensity of the laser beam; βeff, the nonlinear coefficient; α0, the linear absorption coefficient, which can be obtained from the UV-Vis absorption; and Is, the saturation light intensity.

 

Fig. 4. Open-aperture Z-scan results of MoS2 dispersions (a) at 0 rpm with different pulse energies, (b) at 6000 rpm with different pulse energies, and (c) at different rotation speeds. Z-scan results of MoS2 films (d) at 8000 rpm and different pulse energies, at different rotation speeds (e) with 45 nm thickness and (f) 75 nm thickness.

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After fitting the Z-scan curves, the Is value of all MoS2 dispersions is roughly 329  GW/cm2 as the nanosheets are multilayer MoS2 with almost the same thickness [30]. This value is on the same scale as the reported value (Is413±24  GW/cm2) [45]. Similarly, the Is of MoTe2 nanosheet dispersion is 217±11  GW/cm2 at the same condition [24]. Meanwhile, βeff is strongly dependent on the nanosheet size, as presented in Fig. 5(a). The MoS2 dispersion shows SA with a βeff of 4.2×103  cm/GW at 0 rpm, while the calculated βeff is 4.9×102  cm/GW at 6000 rpm for RSA. Similarly, we also observed obvious nonlinear absorption for MoS2 films with different centrifugation speed. The calculated βeff of MoS2 is 158  cm/GW at 2000 rpm, and it is 13  cm/GW at 8000 rpm. With an increase in centrifugation speed, the value of βeff becomes larger due to the increased contribution to RSA.

 

Fig. 5. (a) Calculated results of α0 (red dot) and βeff (blue square), respectively. (b) Imχ(3) and FOM from MoS2 dispersions in red dot and blue square, respectively. (c) Measured α0 (red dot) and βeff (blue square). (d) Imχ(3) and FOM from films with different sizes, which are shown using red dot and blue square, respectively.

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In order to evaluate the performance of the NLO devices, the linear absorption needs to be eliminated. The calculated α0 values are presented in Fig. 5(a). The imaginary part of the third-order NLO susceptibility (Imχ(3)) is defined [46,47] as follows:

Imχ(3)(esu)=(107cλn296π2)βeff,
where λ, c, and n denote laser wavelength, light velocity, and linear refractive index, respectively [48].

By the definition of figure of merit (FOM) for third-order nonlinear absorption, FOM=|Imχ(3)/α0|, Imχ(3), and FOM values of MoS2 nanosheet dispersions are presented in Fig. 5(b), which indicates that both FOM and Imχ(3) increase with the decreased sheet size implying their size dependence of MoS2 dispersion. Further, The FOM and Imχ(3) values for MoS2 film were also investigated as shown in Fig. 5(d) with the film thickness of 45 nm. Apparently, the increase in size results in the increase in Imχ(3) value, making it clear that NLO properties are dependent on size, which is consistent with the results obtained from MoS2 dispersion. However, the FOM value decreases with the increase in size which is due to the improved contribution from RSA.

D. Mechanism of Size-Dependent Nonlinear Absorption

For MoS2, the appearance of SA can be mainly attributed to band-to-band absorption because the nanosheet bandgap is below the excited photon energy. The excited electrons directly move from the valence band (VB) to the conduction band (CB). Meanwhile, the RSA phenomenon is commonly associated with the aforementioned nonlinear scattering, excited state absorption, and TPA. In our experiments, the nonlinear scattering can be ignored [32] due to the 35-fs laser pulse duration and nanojoule-level pulse energy, which will not induce microbubbles from the thermal effect. The excited state absorption process is associated with the triplet state in organic dyes. However, the triplet state can be neglected because the relaxation time is much longer than the pulse width [34,49]. In addition, the TPA lifetime is very short (in picosecond/femtosecond scale), which is consistent with the ultrashort pulse laser utilized in this work. In essence, TPA mainly occurs when the excited photon energy is lower than the bandgap. In this study, the defect state of S vacancies is introduced for MoS2 over 2000 rpm. The S vacancies state can act as a stable state and absorb an excited electron. Therefore, the S vacancy state absorption will take part in the optical process, which could also explain the RSA phenomena at high concentration of S vacancies. In other words, the competition between excited and defect state absorption in MoS2 dispersions and films can be mediated by the concentration of S vacancies.

To confirm the mechanism behind the size-dependent NLO properties of MoS2 dispersions and films, the band structure and density of states (DOS) of MoS2 are presented in Fig. 6 [50]. The CB is mainly formed by Mo4d, while the VB is formed by Mo4d and S3p, in accordance with the previous report [51]. To investigate the influence of S vacancies on electronic properties, monosulfur and disulfur vacancies are introduced and lead to the defect level in the bandgap as shown in Figs. 6(b) and 6(c), which are consistent with the previous reports [29,52]. With the emergence of S vacancies, the CB and VB have not had an evident change, but new defect levels appear below the conduction band minimum (CBM), corresponding to density functional theory results [2,53]. The defect states mainly come from Mo4d orbitals in the DOS spectrum, while the S3p orbits provide few contributions to these defect states in the bandgap [29]. The defect states possess three peaks in the DOS as shown in Fig. 6(c), which are more delocalized compared to that in Fig. 6(b) owing to the disulfur vacancies [28]. The monosulfur and disulfur vacancy will introduce deep levels staying about 0.6 eV below CBM [52]. These defect levels can participate in optical absorption and absorb excited electrons, which agree well with the experimental results [7,54,55]. Under the excitation, the electrons of S vacancies will be excited to the CB because the defect level is close to the CBM [28]. Increased S vacancies with size enhance the DOS of S vacancies, leading to the populating of more electrons from the VB as well as to enhancing nonlinear absorption [7]. Herein, an energy-level model based on the concentration of S vacancies was developed to understand the dynamic process in Fig. 7.

 

Fig. 6. Band structure and DOS results for monolayer MoS2: (a) perfect; (b) with monosulfur vacancy; and (c) with disulfur vacancy.

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Fig. 7. (a) Three-energy-level model of few or few-defect MoS2. (b) Three-energy-level model combined with defect state of S vacancies in MoS2. (c) Three-defect-energy-level diagram at a high concentration of S vacancies in MoS2. Fitting results of (d) MoS2 dispersions at different rotation speeds, MoS2 films (e) with 45 nm thickness and (f) with 75 nm thickness.

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Three-energy-level model (Model 1) in Fig. 7(a) was created to investigate the dynamic process of defect-free samples [49], where S0, S1, and S2 denote the state of ground, first excited, and second excited, respectively; N0 and N1, the population densities of S0 and S1, respectively; σ0 and σ1, cross-section of ground and excited state, respectively; and τ0, the lifetime of first excited state moving to ground state. At low concentrations of S vacancies, the excited electrons are captured by the S vacancy states. Thus, the defect state model (Model 2) was introduced based on Model 1, which is presented in Fig. 7(b), where Sd denotes the vacancy defect state; Nd, the population densities of Sd; and σ2 and σ3, the ground state cross-section and defect state cross-section in defect materials, respectively. τ1 and τ2 denote the lifetime of first excited state to defect state and back to ground state, respectively. For high concentrations of S vacancies, the defect energy-level model (Model 3) is presented in Fig. 7(c). The excited electrons are directly captured in defect state.

Nonlinear propagation equations were defined as a function of pulse energy α(I) [22,56] as

dIdz=α(I)I.

Rate equations and nonlinear propagation based on Models 1–3 can be expressed as shown below.

Model 1 is as follows:

dN0dt=N0σ0Ihν+N1τ0,
dN1dt=N0σ0IhνN1τ0,
dIdz=σ0N0Iσ1N1I,
N=N0+N1.
Model 2 is as follows:
dN0dt=N0σ0IhνN0σ2Ihν+N1τ0+Ndτ2,
dN1dt=N0σ0Ihν+Ndσ3IhνN1τ0N1τ1,
dNddt=N0σ2IhνNdσ3Ihν+N1τ1Ndτ2,
N=N0+N1+Nd.
Model 3 is as follows:
dN0dt=N0σ2Ihν+Ndτ2,
dNddt=N0σ2IhνNdσ3Ihν+N1τ1Ndτ2,
dN1dt=Ndσ3IhνN1τ1,
N=N0+N1+Nd.

The MoS2 dispersion at 0 rpm exhibits a defect-free sample. The MoS2 films with different sizes and a thickness of 75 nm show SA, which can be described by Model 1. σ1/σ0 is vital in assessing SA and RSA. RSA occurs if the absorption cross-section of excited state is larger than that of ground state, which results in optical limiting effects [57]. Otherwise, SA occurs [20,26]. Fitting results of MoS2 dispersions and films, by the Runge–Kutta algorithm [43] based on Model 1, are presented in Figs. 7(d) and 7(f). The fitting parameter (σ1/σ0) is less than one in Table 1 implying an SA. τ0 indicates that the excited electrons return rapidly to the S0, which means it plays a significant role in ground absorption. For MoS2 films with a thickness of 75 nm, τ0 changes from 0.13 to 46.7 ps, leading to a giant SA for a large-size formed film. On the other hand, the transition from SA to RSA was observed at MoS2 films with different sizes but the same thickness of 45 nm, which can be deduced from the competition between excited state and defect state absorption. Fitting these equations based on Model 2 in Fig. 7(e), we defined σ2/σ0 to evaluate the dominated transportation pathway of electrons. If σ2/σ0 is larger than one, the defect state absorption plays a significant role in nonlinear absorption. Then, σ3/σ2 was introduced to assess the SA and RSA. Otherwise, we similarly assess the nonlinear absorption according to the value of σ1/σ0. The fitting results agree well with the explanation based on Model 2. Experimentally, the MoS2 nanosheet possesses a large number of S vacancies over 6000 rpm. σ3/σ2 is also used to assess the SA and RSA based on Model 3. Indeed, an increase in the number of S vacancies results in the increase in defect state absorption, thereby improving the RSA. The fitting results based on different models are consistent with the experimental results in Table 1. They show that the vacancy defect state can absorb an excited electron, which explains the transition from SA to RSA.

Tables Icon

Table 1. Parameters of MoS2 Dispersions and Films

3. CONCLUSIONS

In summary, size-dependent S vacancies are successfully introduced in MoS2 dispersions and films. The size-dependent S vacancies are also confirmed by TEM, Raman spectroscopy, and XPS. The transition from SA to RSA was observed with the increase of S vacancies. Based on the concentration of S vacancies, an energy-level model was developed to understand the dynamic process. The results show that SA and RSA phenomena can be explained by the competition between defect state, excited state, and ground state absorption. To conclude this work, it paves a new way to tune nonlinear photonic devices by defect engineering.

Funding

National Natural Science Foundation of China (11774288, 11974279); Natural Science Foundation of Shaanxi Province (2019JC-25, 2019-JM131, 2019JM-236).

Disclosures

The authors declare no conflicts of interest.

REFERENCES

1. A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015). [CrossRef]  

2. K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014). [CrossRef]  

3. S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013). [CrossRef]  

4. H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014). [CrossRef]  

5. L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019). [CrossRef]  

6. Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016). [CrossRef]  

7. M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014). [CrossRef]  

8. A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015). [CrossRef]  

9. P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017). [CrossRef]  

10. C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018). [CrossRef]  

11. K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017). [CrossRef]  

12. Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017). [CrossRef]  

13. K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017). [CrossRef]  

14. S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012). [CrossRef]  

15. L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019). [CrossRef]  

16. S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018). [CrossRef]  

17. X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019). [CrossRef]  

18. S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017). [CrossRef]  

19. C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020). [CrossRef]  

20. R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016). [CrossRef]  

21. Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010). [CrossRef]  

22. J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016). [CrossRef]  

23. J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017). [CrossRef]  

24. K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014). [CrossRef]  

25. P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015). [CrossRef]  

26. S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016). [CrossRef]  

27. S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014). [CrossRef]  

28. S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016). [CrossRef]  

29. Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013). [CrossRef]  

30. K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015). [CrossRef]  

31. H. Zhang, S. B. Lu, J. Zheng, J. Du, S. C. Wen, D. Y. Tang, and K. P. Loh, “Molybdenum disulfide MoS2 as a broadband saturable absorber for ultra-fast photonics,” Opt. Express 22, 7249–7260 (2014). [CrossRef]  

32. X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012). [CrossRef]  

33. M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017). [CrossRef]  

34. C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019). [CrossRef]  

35. L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014). [CrossRef]  

36. J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013). [CrossRef]  

37. A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015). [CrossRef]  

38. G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016). [CrossRef]  

39. X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014). [CrossRef]  

40. P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019). [CrossRef]  

41. S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015). [CrossRef]  

42. M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017). [CrossRef]  

43. Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014). [CrossRef]  

44. L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019). [CrossRef]  

45. K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013). [CrossRef]  

46. X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018). [CrossRef]  

47. B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018). [CrossRef]  

48. G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018). [CrossRef]  

49. M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013). [CrossRef]  

50. Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018). [CrossRef]  

51. J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004). [CrossRef]  

52. W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013). [CrossRef]  

53. M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016). [CrossRef]  

54. X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018). [CrossRef]  

55. B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014). [CrossRef]  

56. C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019). [CrossRef]  

57. N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013). [CrossRef]  

References

  • View by:
  • |
  • |
  • |

  1. A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
    [Crossref]
  2. K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
    [Crossref]
  3. S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
    [Crossref]
  4. H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
    [Crossref]
  5. L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
    [Crossref]
  6. Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
    [Crossref]
  7. M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
    [Crossref]
  8. A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
    [Crossref]
  9. P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
    [Crossref]
  10. C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
    [Crossref]
  11. K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
    [Crossref]
  12. Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
    [Crossref]
  13. K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
    [Crossref]
  14. S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
    [Crossref]
  15. L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
    [Crossref]
  16. S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
    [Crossref]
  17. X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
    [Crossref]
  18. S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
    [Crossref]
  19. C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
    [Crossref]
  20. R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
    [Crossref]
  21. Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
    [Crossref]
  22. J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
    [Crossref]
  23. J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
    [Crossref]
  24. K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
    [Crossref]
  25. P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
    [Crossref]
  26. S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
    [Crossref]
  27. S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
    [Crossref]
  28. S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016).
    [Crossref]
  29. Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
    [Crossref]
  30. K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
    [Crossref]
  31. H. Zhang, S. B. Lu, J. Zheng, J. Du, S. C. Wen, D. Y. Tang, and K. P. Loh, “Molybdenum disulfide MoS2 as a broadband saturable absorber for ultra-fast photonics,” Opt. Express 22, 7249–7260 (2014).
    [Crossref]
  32. X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
    [Crossref]
  33. M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
    [Crossref]
  34. C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
    [Crossref]
  35. L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
    [Crossref]
  36. J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
    [Crossref]
  37. A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
    [Crossref]
  38. G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
    [Crossref]
  39. X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
    [Crossref]
  40. P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
    [Crossref]
  41. S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
    [Crossref]
  42. M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
    [Crossref]
  43. Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
    [Crossref]
  44. L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
    [Crossref]
  45. K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
    [Crossref]
  46. X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
    [Crossref]
  47. B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
    [Crossref]
  48. G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
    [Crossref]
  49. M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
    [Crossref]
  50. Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
    [Crossref]
  51. J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
    [Crossref]
  52. W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
    [Crossref]
  53. M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
    [Crossref]
  54. X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
    [Crossref]
  55. B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
    [Crossref]
  56. C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
    [Crossref]
  57. N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
    [Crossref]

2020 (1)

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

2019 (7)

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
[Crossref]

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

2018 (7)

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
[Crossref]

G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
[Crossref]

2017 (8)

S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
[Crossref]

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

2016 (7)

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016).
[Crossref]

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

2015 (6)

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

2014 (10)

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

H. Zhang, S. B. Lu, J. Zheng, J. Du, S. C. Wen, D. Y. Tang, and K. P. Loh, “Molybdenum disulfide MoS2 as a broadband saturable absorber for ultra-fast photonics,” Opt. Express 22, 7249–7260 (2014).
[Crossref]

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
[Crossref]

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

2013 (7)

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

2012 (2)

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

2010 (1)

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

2004 (1)

J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
[Crossref]

Addou, R.

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Ajayan, P. M.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Akinwande, D.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Aloukos, P.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Anand, B.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Angelica, A.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Ataca, C.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Bai, J.

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Bakandritsos, A.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Banerjee, S.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Banerjee, S. K.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Bao, Q.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Basko, D. M.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Bechelany, M.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Biswas, S.

S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
[Crossref]

S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
[Crossref]

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Blau, W. J.

B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

Bonaccorso, F.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Bonini, N.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Brennan, B.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Chang, C.

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

Chang, M. J.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Chatterjee, U.

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Chen, B.

Chen, J.

Chen, K.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Chen, Q.

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Chen, S.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Chen, Y.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

Chen, Z.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Cheng, M.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Cheng, P. K.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Chhowalla, M.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Cho, K.

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Choi, J.-Y.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Choi, W.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Coleman, J. N.

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Couris, S.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Cui, Y.

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

Daisuke, K.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Das, R.

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

Der-Hsien, L.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Dong, N.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

Du, J.

Du, W.

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

Fan, J.

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Fan, W.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Feng, L.-P.

L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
[Crossref]

Feng, Y.

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Ferrari, A. C.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Fox, D.

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Fuhr, J. D.

J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
[Crossref]

Gao, F.

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

Ghosh, R.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Gilmore, I. S.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Gong, Y.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Gopinath, P.

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

Grossman, J. C.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Guo, Y.

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

Hanlon, D.

Hasan, T.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

He, C.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

He, D.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

He, F.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

He, M.

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

He, X.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

He, Y.

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Hong, S.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Hong, X.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Hu, Z.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Huang, D.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Huang, J.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

Huang, Y.

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Hwang, W.-S.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Idrobo, J. C.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Jacobsen, K. W.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Jena, D.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Jhon, Y. I.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

Jhon, Y. M.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

Jia, B.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Jiang, B.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Jiang, D.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Jiang, J.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Jiang, T.

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

Jiang, X.-F.

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Jin, C.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Jin, Y. W.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Jinesh, K. B.

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

Jiyoung, N.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

John, H.

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

Jun, X.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Jung, C.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Jung, G.-H.

G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
[Crossref]

Kanehara, M.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Kang, J. S.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Kaplan, D.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Karmakar, S.

S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
[Crossref]

S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
[Crossref]

Kavitha, M. K.

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

Kim, H.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Kim, J.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Kim, J.-S.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Kim, K.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Kim, S.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Kislyakov, I. M.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

Ko, C.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Kole, A. K.

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Kolokithas-Ntoukas, A.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Konar, A.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Kong, J.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Koo, J.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

Krishnan, S. R.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Kuhar, K.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Kumar, P.

P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
[Crossref]

Kumar, S.

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

Kumbhakar, P.

S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
[Crossref]

S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
[Crossref]

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Latham, K.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Lee, J.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Lee, J. H.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Lee, S. Y.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Lei, L.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Li, B.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Li, J.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Li, L.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Li, P.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Li, S.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Liang, Z.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Liaros, N.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Lin, H.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Lin, J.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Lin, J.-F.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Ling, C.

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

Liu, C.

Liu, J.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Liu, Z.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Liu, Z.-T.

L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
[Crossref]

Loh, K. P.

Long, H.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Longo, R. C.

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Lotya, M.

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Lou, J.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Lou, X. W.

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Lu, C.

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

Lu, J.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Lu, S. B.

Lu, Y.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Luce, A.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Ma, S.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Madan, D.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Madhvapathy, S. R.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Makuta, S.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Mason, S. C.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Matin, A.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

McEvoy, N.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

Mei, L.

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Meng, X.

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Miao, F.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Michel, T.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Miele, P.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Mignuzzi, S.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Mu, H.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Najmaei, S.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Nan, H.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Neo, S. T.

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Ni, Z.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Nunzi, J. M.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

O’Neill, A.

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Ogletree, F.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Olsen, T.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Ouyang, Q.

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

Ouyang, Y.

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

Pan, A.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Pandey, M.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Pantelides, S. T.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Park, J.

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

Park, Q. H.

G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
[Crossref]

Philip, R.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

Pimenta, M. A.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Podila, R.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Polavarapu, L.

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Pollard, A. J.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Popa, D.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Privitera, G.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Qiao, T.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Qin, S.

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

Qin, Z.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Qiu, J.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Quan, C.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Rafik, A.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Raghunathanan, R.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Rai, A.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Rao, A. M.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Rasmussen, F. A.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Reddy, G. B.

P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
[Crossref]

Register, L. F.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Ren, Z.

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

Richards, D.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Ries, L.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Roy, A.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Roy, D.

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Saffarzadeh, A.

S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016).
[Crossref]

Sahoo, P. K.

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

Sai, S. S.

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Salameh, C.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Salehi, S.

S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016).
[Crossref]

Santosh, K.

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Santosh, K. C.

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Saul, A.

J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
[Crossref]

Seifert, T.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Senge, M. O.

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

Shi, L.

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

Shi, S. F.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Shi, Y.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Shivananju, B. N.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Si, K.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

Singh, A.

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

Singh, M.

P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
[Crossref]

Sofo, J. O.

J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
[Crossref]

Song, Y.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Su, J.

L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
[Crossref]

Suh, J.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Sun, X.

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Sun, Y.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Sun, Y. Y.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

Sun, Z.

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Szabo, T.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Szydlowska, B. M.

B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
[Crossref]

Tachibana, Y.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Taha-Tijerina, J.

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Tan, P.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Tang, C. Y.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Tang, D.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Tang, D. Y.

Teranishi, T.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Thygesen, K. S.

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Tian, X.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Tiwary, C. S.

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Tongay, S.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Torrisi, F.

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Tsang, Y. H.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Tywoniuk, B.

B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
[Crossref]

Vajtai, R.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Valsaraj, A.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

Veamatahau, A.

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

Venkatesan, T.

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Vinod, S.

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

Voiry, D.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Wallace, R. M.

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Wang, A.

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Wang, C.

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

Wang, F.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

Wang, H.

Wang, J.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Wang, K.

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Wang, L.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

Wang, Q.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Wang, R.

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Wang, S.

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Wang, W.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Wang, X.

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Wang, X. Y.

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Wang, Y.

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Wang, Z.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

Wei, R.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Wen, S. C.

Wu, J.

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Wu, K.

Wu, X. Z.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Wu, Z.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Xie, J.

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Xie, Y.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Xu, Q.-H.

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Xu, X.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Xu, Y.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Yakobson, B. I.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Yang, J.

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Yang, P.

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

Yang, T.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Yao, Z.

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Ye, G.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

Yoo, J.-B.

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Yoo, S.

G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
[Crossref]

You, Y.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Yu, H.

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

Yu, Y.

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

Zawadzka, M.

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

Zboril, R.

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Zeng, G.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Zhan, J.

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

Zhan, Y.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

Zhang, H.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

H. Zhang, S. B. Lu, J. Zheng, J. Du, S. C. Wen, D. Y. Tang, and K. P. Loh, “Molybdenum disulfide MoS2 as a broadband saturable absorber for ultra-fast photonics,” Opt. Express 22, 7249–7260 (2014).
[Crossref]

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Zhang, H. L.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Zhang, K.

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

Zhang, L.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Zhang, Q.

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

Zhang, R.

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

Zhang, S.

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

Zhang, W.

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

Zhang, X.

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

S. Zhang, X. Zhang, H. Wang, B. Chen, K. Wu, K. Wang, D. Hanlon, J. N. Coleman, J. Chen, L. Zhang, and J. Wang, “Size-dependent saturable absorption and mode-locking of dispersed black phosphorus nanosheets,” Opt. Mater. Express 6, 3159–3168 (2016).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Zhang, Y.

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

Zhao, M.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

Zhao, Q.

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

Zhao, W.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Zheng, J.

Zheng, T.

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

Zhou, C.

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

Zhou, J.

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Zhou, K. G.

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Zhou, M.

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Zhou, W.

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Zhou, Y.

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

X. Xu, M. He, C. Quan, R. Wang, C. Liu, Q. Zhao, Y. Zhou, J. Bai, and X. Xu, “Saturable absorption properties of ReS2 films and mode-locking application based on double-covered ReS2 micro fiber,” J. Lightwave Technol. 36, 5130–5136 (2018).
[Crossref]

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

Zhu, L.

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

Zou, X.

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

Zu, H.

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

Zu, X.

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

ACS Appl. Mater. Interfaces (2)

P. Li, Y. Chen, T. Yang, Z. Wang, H. Lin, Y. Xu, L. Li, H. Mu, B. N. Shivananju, Y. Zhang, Q. Zhang, A. Pan, S. Li, D. Tang, B. Jia, H. Zhang, and Q. Bao, “Two-dimensional CH3NH3PbI3 perovskite nanosheets for ultrafast pulsed fiber lasers,” ACS Appl. Mater. Interfaces 9, 12759–12765 (2017).
[Crossref]

K. Chen, A. Roy, A. Rai, A. Valsaraj, X. Meng, F. He, X. Xu, L. F. Register, S. Banerjee, and Y. Wang, “Carrier trapping by oxygen impurities in molybdenum diselenide,” ACS Appl. Mater. Interfaces 10, 1125–1131 (2017).
[Crossref]

ACS Appl. Nano Mater. (1)

P. Kumar, M. Singh, and G. B. Reddy, “Oxidized core-shell MoO2–MoS2 nanostructured thin films for hydrogen evolution,” ACS Appl. Nano Mater. 3, 711–723 (2019).
[Crossref]

ACS Nano (4)

K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).
[Crossref]

H. Nan, Z. Wang, W. Wang, Z. Liang, Y. Lu, Q. Chen, D. He, P. Tan, F. Miao, X. Wang, and Z. Ni, “Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding,” ACS Nano 8, 5738–5745 (2014).
[Crossref]

L. Li, Z. Qin, L. Ries, S. Hong, T. Michel, J. Yang, C. Salameh, M. Bechelany, P. Miele, D. Kaplan, M. Chhowalla, and D. Voiry, “Role of sulfur vacancies and undercoordinated Mo regions in MoS2 nanosheets toward the evolution of hydrogen,” ACS Nano 13, 6824–6834 (2019).
[Crossref]

Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, and A. C. Ferrari, “Graphene mode-locked ultrafast laser,” ACS Nano 4, 803–810 (2010).
[Crossref]

ACS Photon. (2)

J. Huang, N. Dong, S. Zhang, Z. Sun, W. Zhang, and J. Wang, “Nonlinear absorption induced transparency and optical limiting of black phosphorus nanosheets,” ACS Photon. 4, 3063–3070 (2017).
[Crossref]

B. M. Szydłowska, B. Tywoniuk, and W. J. Blau, “Size-dependent nonlinear optical response of black phosphorus liquid phase exfoliated nanosheets in nanosecond regime,” ACS Photon. 5, 3608–3612 (2018).
[Crossref]

Adv. Funct. Mater. (1)

J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, and J. H. Lee, “Near-infrared saturable absorption of defective bulk-structured WTe2 for femtosecond laser mode-locking,” Adv. Funct. Mater. 26, 7454–7461 (2016).
[Crossref]

Adv. Mater. (2)

S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).
[Crossref]

J. Xie, H. Zhang, S. Li, R. Wang, X. Sun, M. Zhou, J. Zhou, X. W. Lou, and Y. Xie, “Defect-rich MoS2 ultrathin nanosheets with additional active edge sites for enhanced electrocatalytic hydrogen evolution,” Adv. Mater. 25, 5807–5813 (2013).
[Crossref]

Adv. Mater. Interfaces (1)

C. Quan, C. Lu, C. He, X. Xu, Y. Huang, Q. Zhao, and X. Xu, “Band alignment of MoTe2/MoS2 nanocomposite films for enhanced nonlinear optical performance,” Adv. Mater. Interfaces 6, 1801733 (2019).
[Crossref]

Adv. Opt. Mater. (2)

P. Kumbhakar, A. K. Kole, C. S. Tiwary, S. Biswas, S. Vinod, J. Taha-Tijerina, U. Chatterjee, and P. M. Ajayan, “Nonlinear optical properties and temperature-dependent uv-vis absorption and photoluminescence emission in 2D hexagonal boron nitride nanosheets,” Adv. Opt. Mater. 3, 828–835 (2015).
[Crossref]

C. He, L. Zhu, Q. Zhao, Y. Huang, Z. Yao, W. Du, Y. He, S. Zhang, and X. Xu, “Competition between free carriers and excitons mediated by defects observed in layered WSe2 crystal with time-resolved terahertz spectroscopy,” Adv. Opt. Mater. 6, 800290 (2018).
[Crossref]

Appl. Surf. Sci. (2)

S. Karmakar, S. Biswas, and P. Kumbhakar, “A comparison of temperature dependent photoluminescence and photo-catalytic properties of different MoS2 nanostructures,” Appl. Surf. Sci. 455, 379–391 (2018).
[Crossref]

C. Lu, C. Quan, K. Si, X. Xu, C. He, Q. Zhao, Y. Zhan, and X. Xu, “Charge transfer in graphene/WS2 enhancing the saturable absorption in mixed heterostructure films,” Appl. Surf. Sci. 479, 1161–1168 (2019).
[Crossref]

Chem. Mater. (1)

Y. Ouyang, C. Ling, Q. Chen, Z. Wang, L. Shi, and J. Wang, “Activating inert basal planes of MoS2 for hydrogen evolution reaction through the formation of different intrinsic defects,” Chem. Mater. 28, 4390–4396 (2016).
[Crossref]

Coord. Chem. Rev. (1)

L. Lei, D. Huang, G. Zeng, M. Cheng, D. Jiang, C. Zhou, S. Chen, and W. Wang, “A fantastic two-dimensional MoS2 material based on the inert basal planes activation: electronic structure, synthesis strategies, catalytic active sites, catalytic and electronics properties,” Coord. Chem. Rev. 399, 213020 (2019).
[Crossref]

J. Alloys Compd. (1)

L.-P. Feng, J. Su, and Z.-T. Liu, “Effect of vacancies on structural, electronic and optical properties of monolayer MoS2: a first-principles study,” J. Alloys Compd. 613, 122–127 (2014).
[Crossref]

J. Lightwave Technol. (1)

J. Mater. Chem. C (1)

Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).
[Crossref]

J. Phys. Chem. A (1)

M. Zawadzka, J. Wang, W. J. Blau, and M. O. Senge, “Modeling of nonlinear absorption of 5, 10-A2B2 porphyrins in the nanosecond regime,” J. Phys. Chem. A 117, 15–26 (2013).
[Crossref]

J. Phys. Chem. C (4)

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

M. He, C. Quan, C. He, Y. Huang, L. Zhu, Z. Yao, S. Zhang, J. Bai, and X. Xu, “Enhanced nonlinear saturable absorption of MoS2/graphene nanocomposite films,” J. Phys. Chem. C 121, 27147–27153 (2017).
[Crossref]

N. Liaros, P. Aloukos, A. Kolokithas-Ntoukas, A. Bakandritsos, T. Szabo, R. Zboril, and S. Couris, “Nonlinear optical properties and broadband optical power limiting action of graphene oxide colloids,” J. Phys. Chem. C 117, 6842–6850 (2013).
[Crossref]

Z. Wu, W. Zhao, J. Jiang, T. Zheng, Y. You, J. Lu, and Z. Ni, “Defect activated photoluminescence in WSe2 monolayer,” J. Phys. Chem. C 121, 12294–12299 (2017).
[Crossref]

J. Phys. Chem. Lett. (1)

X.-F. Jiang, L. Polavarapu, S. T. Neo, T. Venkatesan, and Q.-H. Xu, “Graphene oxides as tunable broadband nonlinear optical materials for femtosecond laser pulses,” J. Phys. Chem. Lett. 3, 785–790 (2012).
[Crossref]

Laser Photon. Rev. (1)

L. Wang, S. Zhang, N. McEvoy, Y. Y. Sun, J. Huang, Y. Xie, N. Dong, X. Zhang, I. M. Kislyakov, J. M. Nunzi, L. Zhang, and J. Wang, “Nonlinear optical signatures of the transition from semiconductor to semimetal in PtSe2,” Laser Photon. Rev. 13, 1900052 (2019).
[Crossref]

Nano Lett. (3)

G. Ye, Y. Gong, J. Lin, B. Li, Y. He, S. T. Pantelides, W. Zhou, R. Vajtai, and P. M. Ajayan, “Defects engineered monolayer MoS2 for improved hydrogen evolution reaction,” Nano Lett. 16, 1097–1103 (2016).
[Crossref]

W. Zhou, X. Zou, S. Najmaei, Z. Liu, Y. Shi, J. Kong, J. Lou, P. M. Ajayan, B. I. Yakobson, and J. C. Idrobo, “Intrinsic structural defects in monolayer molybdenum disulfide,” Nano Lett. 13, 2615–2622 (2013).
[Crossref]

M. Pandey, F. A. Rasmussen, K. Kuhar, T. Olsen, K. W. Jacobsen, and K. S. Thygesen, “Defect-tolerant monolayer transition metal dichalcogenides,” Nano Lett. 16, 2234–2239 (2016).
[Crossref]

Nanophotonics (1)

G.-H. Jung, S. Yoo, and Q. H. Park, “Measuring the optical permittivity of two-dimensional materials without a priori knowledge of electronic transitions,” Nanophotonics 8, 263–270 (2018).
[Crossref]

Nanoscale (4)

Q. Zhao, Y. Guo, Y. Zhou, Z. Yao, Z. Ren, J. Bai, and X. Xu, “Band alignments and heterostructures of monolayer transition metal trichalcogenides MX3 (M = Zr, Hf; X = S, Se) and dichalcogenides MX2 (M = Tc, Re; X=S, Se) for solar applications,” Nanoscale 10, 3547–3555 (2018).
[Crossref]

X. Zhang, S. Zhang, Y. Xie, J. Huang, L. Wang, Y. Cui, and J. Wang, “Tailoring the nonlinear optical performance of two-dimensional MoS2 nanofilms via defect engineering,” Nanoscale 10, 17924–17932 (2018).
[Crossref]

R. Wei, H. Zhang, X. Tian, T. Qiao, Z. Hu, Z. Chen, X. He, Y. Yu, and J. Qiu, “MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser,” Nanoscale 8, 7704–7710 (2016).
[Crossref]

K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, and J. Wang, “Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors,” Nanoscale 6, 10530–10535 (2014).
[Crossref]

Nanotechnology (1)

K. C. Santosh, R. C. Longo, R. Addou, R. M. Wallace, and K. Cho, “Impact of intrinsic atomic defects on the electronic structure of MoS2 monolayers,” Nanotechnology 25, 375703 (2014).
[Crossref]

Nat. Commun. (1)

S. Kim, A. Konar, W.-S. Hwang, J. H. Lee, J. Lee, J. Yang, C. Jung, H. Kim, J.-B. Yoo, J.-Y. Choi, Y. W. Jin, S. Y. Lee, D. Jena, W. Choi, and K. Kim, “High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals,” Nat. Commun. 3, 1011 (2012).
[Crossref]

Nat. Nanotechnol. (1)

X. Hong, J. Kim, S. F. Shi, Y. Zhang, C. Jin, Y. Sun, S. Tongay, J. Wu, Y. Zhang, and F. Wang, “Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures,” Nat. Nanotechnol. 9, 682–686 (2014).
[Crossref]

npj 2D Mater. Appl. (1)

K. Chen, R. Ghosh, X. Meng, A. Roy, J.-S. Kim, F. He, S. C. Mason, X. Xu, J.-F. Lin, D. Akinwande, S. K. Banerjee, and Y. Wang, “Experimental evidence of exciton capture by mid-gap defects in CVD grown monolayer MoSe2,” npj 2D Mater. Appl. 1, 15 (2017).
[Crossref]

Opt. Express (1)

Opt. Mater. (3)

X. Zhang, R. Zhang, Y. Zhang, T. Jiang, and S. Qin, “Tunable photoluminescence of bilayer MoS2 via interlayer twist,” Opt. Mater. 94, 213–216 (2019).
[Crossref]

S. Karmakar, S. Biswas, and P. Kumbhakar, “Low power continuous-wave nonlinear optical effects in MoS2 nanosheets synthesized by simple bath ultrasonication,” Opt. Mater. 73, 585–594 (2017).
[Crossref]

C. Y. Tang, P. K. Cheng, X. Y. Wang, S. Ma, H. Long, and Y. H. Tsang, “Size-dependent nonlinear optical properties of atomically thin PtS2 nanosheet,” Opt. Mater. 101, 109694 (2020).
[Crossref]

Opt. Mater. Express (1)

Phys. Chem. Chem. Phys. (4)

Y. Zhou, P. Yang, H. Zu, F. Gao, and X. Zu, “Electronic structures and magnetic properties of MoS2 nanostructures: atomic defects, nanoholes, nanodots and antidots,” Phys. Chem. Chem. Phys. 15, 10385–10394 (2013).
[Crossref]

M. K. Kavitha, K. B. Jinesh, R. Philip, P. Gopinath, and H. John, “Defect engineering in ZnO nanocones for visible photoconductivity and nonlinear absorption,” Phys. Chem. Chem. Phys. 16, 25093–25100 (2014).
[Crossref]

A. Veamatahau, B. Jiang, T. Seifert, S. Makuta, K. Latham, M. Kanehara, T. Teranishi, and Y. Tachibana, “Origin of surface trap states in CdS quantum dots: relationship between size dependent photoluminescence and sulfur vacancy trap states,” Phys. Chem. Chem. Phys. 17, 2850–2858 (2015).
[Crossref]

B. Anand, S. R. Krishnan, R. Podila, S. S. Sai, A. M. Rao, and R. Philip, “The role of defects in the nonlinear optical absorption behavior of carbon and ZnO nanostructures,” Phys. Chem. Chem. Phys. 16, 8168–8177 (2014).
[Crossref]

Phys. Rev. B (1)

S. Mignuzzi, A. J. Pollard, N. Bonini, B. Brennan, I. S. Gilmore, M. A. Pimenta, D. Richards, and D. Roy, “Effect of disorder on Raman scattering of single-layer MoS2,” Phys. Rev. B 91, 195411 (2015).
[Crossref]

Phys. Rev. Lett. (1)

J. D. Fuhr, A. Saul, and J. O. Sofo, “Scanning tunneling microscopy chemical signature of point defects on the MoS2 (0001) surface,” Phys. Rev. Lett. 92, 026802 (2004).
[Crossref]

RSC Adv. (1)

A. Singh, S. Kumar, R. Das, and P. K. Sahoo, “Defect-assisted saturable absorption characteristics in Mn doped ZnO nano-rods,” RSC Adv. 5, 88767–88772 (2015).
[Crossref]

Sci. Rep. (1)

S. Tongay, J. Suh, C. Ataca, W. Fan, A. Luce, J. S. Kang, J. Liu, C. Ko, R. Raghunathanan, J. Zhou, F. Ogletree, J. Li, J. C. Grossman, and J. Wu, “Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons,” Sci. Rep. 3, 2657 (2013).
[Crossref]

Science (1)

A. Matin, L. Der-Hsien, K. Daisuke, X. Jun, A. Angelica, N. Jiyoung, S. R. Madhvapathy, A. Rafik, K. Santosh, and D. Madan, “Near-unity photoluminescence quantum yield in MoS2,” Science 350, 1065–1068 (2015).
[Crossref]

Small (1)

K. G. Zhou, M. Zhao, M. J. Chang, Q. Wang, X. Z. Wu, Y. Song, and H. L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 694–701 (2015).
[Crossref]

Surf. Sci. (1)

S. Salehi and A. Saffarzadeh, “Atomic defect states in monolayers of MoS2 and WS2,” Surf. Sci. 651, 215–221 (2016).
[Crossref]

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Figures (7)

Fig. 1.
Fig. 1. (a) Concentrations of MoS2 dispersion at different rotation speeds with related optical images inserted. (b) Tauc plot of MoS2 dispersions. (c) Size and height of MoS2 dispersions at different rotation speeds. (d), (g) AFM image and height profile of MoS2 at 2000 rpm. (e), (h) AFM image and height profile of  MoS2 at 4000 rpm. (f), (i) AFM image and height profile of MoS2 at 6000 rpm. The number indicates the different nanosheet.
Fig. 2.
Fig. 2. Representative TEM images of MoS2 dispersions at (a) 0, (b) 2000, (c) 4000, (d) 6000, and (e) 8000 rpm. (f) High-resolution TEM image of MoS2 nanosheet at 6000 rpm. (g) TEM image of ultrathin layer of MoS2 defect at 8000 rpm; elemental mapping of (h) Mo (i) S.
Fig. 3.
Fig. 3. (a) High-resolution XPS spectra of MoS2 films. (b) XRD patterns of MoS2 films. (c) Raman spectra of MoS2 films. (d) Raman shift of E2g1 and A1g. (e) UV-Vis absorption spectra of MoS2 films. (f) Tauc plot obtained from UV-Vis absorption spectra of MoS2 films with an increase in centrifugation speed.
Fig. 4.
Fig. 4. Open-aperture Z-scan results of MoS2 dispersions (a) at 0 rpm with different pulse energies, (b) at 6000 rpm with different pulse energies, and (c) at different rotation speeds. Z-scan results of MoS2 films (d) at 8000 rpm and different pulse energies, at different rotation speeds (e) with 45 nm thickness and (f) 75 nm thickness.
Fig. 5.
Fig. 5. (a) Calculated results of α0 (red dot) and βeff (blue square), respectively. (b) Imχ(3) and FOM from MoS2 dispersions in red dot and blue square, respectively. (c) Measured α0 (red dot) and βeff (blue square). (d) Imχ(3) and FOM from films with different sizes, which are shown using red dot and blue square, respectively.
Fig. 6.
Fig. 6. Band structure and DOS results for monolayer MoS2: (a) perfect; (b) with monosulfur vacancy; and (c) with disulfur vacancy.
Fig. 7.
Fig. 7. (a) Three-energy-level model of few or few-defect MoS2. (b) Three-energy-level model combined with defect state of S vacancies in MoS2. (c) Three-defect-energy-level diagram at a high concentration of S vacancies in MoS2. Fitting results of (d) MoS2 dispersions at different rotation speeds, MoS2 films (e) with 45 nm thickness and (f) with 75 nm thickness.

Tables (1)

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Table 1. Parameters of MoS2 Dispersions and Films

Equations (15)

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α(I)=α01+(I/Is)+βeffI,
Imχ(3)(esu)=(107cλn296π2)βeff,
dIdz=α(I)I.
dN0dt=N0σ0Ihν+N1τ0,
dN1dt=N0σ0IhνN1τ0,
dIdz=σ0N0Iσ1N1I,
N=N0+N1.
dN0dt=N0σ0IhνN0σ2Ihν+N1τ0+Ndτ2,
dN1dt=N0σ0Ihν+Ndσ3IhνN1τ0N1τ1,
dNddt=N0σ2IhνNdσ3Ihν+N1τ1Ndτ2,
N=N0+N1+Nd.
dN0dt=N0σ2Ihν+Ndτ2,
dNddt=N0σ2IhνNdσ3Ihν+N1τ1Ndτ2,
dN1dt=Ndσ3IhνN1τ1,
N=N0+N1+Nd.

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