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Abstract
Polarization properties of silver nanowire (AgNW)/polymer composite films are investigated by spectroscopic polarimetry, with special attention to their potential application as the transparent conductive electrode of touch screen devices. The analysis of the Mueller matrix decomposition for preferentially oriented AgNW networks shows linear diattenuation and retardance, in addition to depolarization due to the scattering of light by AgNWs. Diattenuation, retardance and depolarization increases with increasing loading amounts of AgNWs. Conversely, depolarization decreases when the diameter of the AgNWs decreases. These polarization properties have an impact on the polarization state of the transmitted light. When applied to a model of liquid crystal display (LCD) with in-cell touch screen (AgNW composite film is placed between crossed linear polarizers), this results in light leakage. However, such leakage (transmittance) can be reduced to 7 × 10−4% by using AgNWs with a diameter of less than or equal to 23 nm, in a film with a sheet resistance of 50Ω/sq, and by aligning the optic axis of the composite film with the transmission axis of the polarizers.
© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
1. Introduction
Silver nanowire (AgNW) networks exhibit high optical transparency and low electrical resistivity, which make them an optimal candidate to replace the industry standard Indium Tin Oxide (ITO) as the next generation of Transparent Conductive Electrodes (TCE) [1–4]. Contrary to ITO films which are brittle, AgNW-based films have improved flexibility and resilience [5–7], therefore showing potential for use in devices with flexible displays. Furthermore, AgNW-networks-based transparent conductive films can be fabricated by cost-effective wet-coating methods [8]. The optical and electrical properties of AgNW networks have been investigated by many authors, both experimentally and theoretically [9–20]. Transmittance and sheet resistance depend on various parameters, including the diameter (D), length (L), aspect ratio (L/D) and loading amount of the AgNWs. For example, sheet resistance strongly depends on the length and loading amount of the AgNWs, whereas transmittance is inversely proportional to the loading amount [9].
Previous works discussed the optical properties of AgNW networks such as transmittance and haze [15–17] but did not include a comprehensive explanation of their polarization properties, notably diattenuation, retardance and depolarization. Pioneering research on the polarization characteristics of spheroidal metal particles and metal nanorods was conducted by Nirmalya Ghosh and Nikolay G. Khlebtsov et al [21–25]. However, we do not know of any report dedicated specifically to silver nanowires. Characterizing the polarization properties of AgNW networks is of fundamental importance for potential industrial applications and may boost their use in optoelectronic devices. For example, in Liquid Crystal Displays (LCDs) with in-cell touch screen technology, the TCE is placed between crossed linear polarizers [26]. In Organic Light Emitting Diode (OLED) displays, the TCE is placed under a circular polarizer to ensure anti-reflection on the metal electrode [27]. The polarization properties of the TCE cause changes in the polarization state of transmitted and reflected light. This results, on the one hand, in light leakage (transmittance) for the black image of LCDs and, on the other hand, increases the reflectance of OLED displays. Our aim in studying the polarization properties of TCEs is to minimize such effects.
We have developed an AgNW/photosensitive polymer composite film that allows conductive patterning on a range of base materials. The composite films fabricated by roll-to-roll slot die-coating exhibit optical and electrical anisotropy depending on the coating conditions. Previously, we discovered and reported that the optical and electrical anisotropy of AgNW networks depend on the orientation of AgNWs in the polymer matrix [28–29].
In this paper, we investigate the influence of the loading amount and diameter of AgNWs on their polarization properties. Mueller matrices can be used to describes the transfer function of any medium interacting with polarized light. Using spectroscopic polarimetry, we measure spectral Mueller matrices of the composite films, by varying the loading amount and diameter of the AgNWs. Subsequently, we apply the polar decomposition methods [30] to quantify diattenuation, retardance and depolarization within the composite films. Diattenuation is defined as the differential attenuation of the orthogonal linear polarizations between horizontal/vertical, +45°/-45°, and orthogonal circular polarizations between left and right. Retardance measures phase shifts between orthogonal linear polarizations and circular polarizations. Depolarization refers to loss of polarization due to randomization in polarization. Diattenuation and retardance are due to the anisotropic orientation of the AgNWs in the polymer matrix. Light scattering by the AgNWs induces partial depolarization in AgNW-based composite films. Finally, we investigate the phenomenon of light leakage occurring when the sample is placed between crossed linear polarizers, to study the potential applications of AgNW/polymer composite films in in-cell touch screen LCDs.
2. Experimental section
2.1 Materials
The AgNWs used in this study were obtained from Cambrios Advanced Materials Corporation. AgNW composite films are fabricated using two-step slot die-coating. First, an aqueous solution of AgNWs is coated on a base film and dried. Additional coating of a photosensitive acrylic polymer is then applied on top of the AgNWs [29]. The polymer protects the AgNWs from environmental exposure and can be patterned onto any substrate.
Seven samples are comprehensively investigated. These samples can be divided into 2 groups according to their properties. Their properties are shown in Table 1. On the one hand, samples A, B and G show comparable sheet resistance for different diameters of AgNWs. Figure 1 (a, b, c) shows dark-field optical microscope images of Samples A, B and G, respectively.
Table 1. Properties of the AgNWs/polymer composite film samples used in this study.
Fig. 1. Typical dark-field optical microscopy images of Samples A, B and G (Panels a), b) and c), respectively). The X and Y directions correspond to the lengthwise and crosswise directions of the composite films, respectively.
On the other hand, Samples B – F contain the same AgNWs, but with different loading amounts. As the loading amount increases (from Sample B to Sample F), transmittance and sheet resistance of the composite films both decrease. Application to touch screens smaller than 12 inches requires a sheet resistance of about 50 Ω/sq. or more [31]. Therefore, even the largest values of the sheet resistance considered in this study (46.8, 47.6 and 54.5 Ω/sq for Samples A, B and G, respectively), are low enough for touch screen applications. Samples with significantly lower sheet resistance (Samples C – F) are compared to Samples A, B and G, to better illustrate the optical properties of AgNWs. All samples exhibit electrical anisotropy due to preferential orientation of the AgNWs along the lengthwise direction of the composite films, with a lengthwise direction sheet resistance value smaller than that of the crosswise direction.
Optical characterization is carried out using these samples, in which composite films are laminated to the substrate upside-down, with the AgNWs on top. The substrates used for optical measurements are 1.0 mm-thick quartz glass.
2.2 Optical measurements
Polarized extinction (absorption and scattering) spectra, as a function of the in-plane rotation, are measured using an Agilent Cary 7000 Universal Measurement Spectrophotometer equipped with a Glan-Taylor calcite prism polarizer. Extinction is measured over the wavelength range 300–1500 nm, through a circular aperture with a diameter of 20 mm.
Spectral Mueller matrices are measured using a spectroscopic polarimeter (“Poxi-spectra”, manufactured by Tokyo instruments Inc.). The Mueller matrix measurement system is composed of a light source, a polarization state generator (PSG), an AgNW/polymer composite film sample, a polarization state analyzer (PSA) and a spectrometer. The PSG is used to generate the elliptical polarization states, subsequently analyzed using the PSA. The 4 × 4 spectral Mueller matrices are constructed using the multiple measurements performed with the combination of the PSG and the PSA, over the wavelength range 400–900 nm.
To determine the diattenuation, retardance and depolarization within the composite film, we apply the polar decomposition technique to the measured Mueller matrix. The depolarization, as estimated by the Mueller matrix decomposition of the AgNW composite film, is very small, and the measurements are extremely noisy. Therefore, we use the following method to estimate its value. We decompose the transfer function of the composite film into three components, each representing a distinct effect on the transmitted light: linear diattenuation, linear retardance and partial depolarization. The optic axis of each component is aligned with the X axis of the reference frame. The corresponding Mueller matrix decomposition is:
The composite film is placed between ideal linear polarizers, with two configurations (Fig. 2): parallel polarizers, aligned with the X axis of the reference frame, and crossed polarizers. The resulting Stokes vectors of transmitted light, S0 and S90 for the parallel and crossed cases, respectively, can be described as:
The total intensity of the outgoing light (transmittance), for the parallel $S_0^0$ and crossed $S_{90}^0$ polarizers cases, respectively, is expressed as:
The degree of depolarization, ${d_1},\;\ $can be calculated from $S_0^0$ and $S_{90}^0$ as: For these measurements, a pair of high-extinction ratio Glan-Thompson polarizers are used. Transmission spectra are measured using a polarization optical system and spectrometer (“RETS 100”, manufactured by Otsuka Electronics Co., Ltd.). The optic axes of the composite film are aligned with the transmission axis of one of the polarizers to eliminate retardance. Figure 2 (a, b) shows the transmission spectra of Sample F when placed between parallel ($S_0^0$) and crossed ($S_{90}^0$) polarizers, respectively. The transmission spectra of the pair of polarizers, without the sample, are also shown in Fig. 2.Fig. 2. Transmission spectrum of Sample F set between a) parallel and b) crossed polarizers. The dashed black line represents the transmission spectrum of the pair of polarizers (without sample). The insets in both panels show the direction of the transmission axis of each polarizer and the optic axes (X, Y) of the sample. The X axis of the reference frame is aligned with the lengthwise direction of the composite film (inset, blue arrow), and the perpendicular Y axis with the crosswise direction of the sample (inset, red arrow). By design, the transmission axis of the incident-side polarizer is aligned with the lengthwise direction of the film for both configurations.
3. Result and discussion
3.1 Extinction spectra
Initially, to examine the optical properties and anisotropy of AgNW composite films, polarized optical extinction spectra were measured as a function of in-plane rotation. Figure 3 shows the normal-incidence polarized extinction spectra of Sample F, color-coded for ten distinct values of the polarization angle. Samples fabricated by slot die-coating exhibit polarization-dependent extinction spectra [28–29]. Distinctive features of the spectra, created by surface plasmon resonances of the AgNWs, can be seen in Fig. 3. One is an extinction band attributed to localized surface plasmon resonances, which arise from electric oscillation along the short axis of the AgNWs (transverse mode) [20,32–34]. This can be seen around 383 nm (dipole resonance), with a shoulder at 360 nm (quadrupole resonance). The other feature is a slight upward slope in the visible to near-infrared spectral region. This might be attributed to electric oscillation along the long axis of the AgNWs (longitudinal mode) [20,32–34]. Extinction in the near-UV (transverse mode) increases from a minimum value at 0° (lengthwise direction of the composite film) to its maximum at 90° (crosswise direction), whereas extinction in the near-IR (longitudinal mode) shows a maximum at 0° and a minimum at 90°. Figure 3 thus indicates that the longitudinal mode is strong in the lengthwise direction of the composite film while, conversely, the transverse mode is stronger in the crosswise direction. These results confirm that AgNWs are preferentially oriented in the lengthwise direction of the composite film.
Fig. 3. Normal incidence, polarized extinction spectra as a function of the polarization angle of Sample F. Inset figure represents the polarization angle of the incident light, color-coded according to the polarization angle of the incident light. The changeover point between the InGaAs and Si detectors used in the NIR and UV/vis spectral regions, respectively, is located at 900 nm. The measurements near this point (900–940 nm) are too noisy to be used, thus these data are not shown.
3.2 Polarization properties
To explore the polarization properties of the composite films, 4 × 4 Mueller matrices are constructed for each sample. Figure 4 shows the measured Mueller matrix elements of Sample F, at azimuthal angles of 0°, 45° and 90°. The azimuthal angle of 0° corresponds to the lengthwise direction of the composite film. Near-zero values are consistently found for both 2 × 2 off-diagonal blocks, (M13, M14, M23, M24) and (M31, M32, M41, M42), at 0° and 90°. This confirms that the lengthwise and crosswise directions of the film are aligned with the optic axes. The non-zero values measured for the symmetric pairs M12 / M21, at 0° and 90°, and M13 / M31, at 45°, indicate linear diattenuation within the composite film, while the results for the pair M24 / M42, at 45°, and M34 / M43, at 0° and 90°, show linear retardance. Furthermore, the near-zero values for the M14 / M41 and M23 / M32 pairs indicate, respectively, low circular diattenuation and low optical rotation.
Fig. 4. Spectroscopic Mueller matrix elements of Sample F measured at azimuthal angles of 0° (blue solid line), 45° (green dotted line) and 90° (red dot-dash line). An azimuth of 0° corresponds to the lengthwise direction of the composite film.
The measured Mueller matrix elements are then decomposed to characterize the diattenuation, retardance and depolarization properties of the AgNW/polymer composite films, as explained in Section 2.2.
The first result of this decomposition analysis is that circular diattenuation and circular retardance effects can be neglected. We explain this result by the achiral nature of the composite film samples. Figure 5 a) shows the spectral dependence of the absolute value of linear diattenuation on the loading amount of AgNWs in Samples B – F. The shape of the diattenuation spectrum for all samples shows a minimum around 460 nm, which is the isosbestic point of the extinction spectra shown in Fig. 3. As the loading amount of AgNWs increases, the diattenuation of the composite films increases as well. Figure 5 b) shows the orientation of the linear diattenuation axis (transmission axis) of Sample F with respect to the X axis of the reference frame. The direction of the transmission axis changes from 0° (lengthwise direction) below 460 nm to an orthogonal orientation of 90° (crosswise direction) above. This confirms our findings, illustrated in Fig. 3, that two orthogonal electric oscillation modes occur within the AgNW/polymer composite films.
Fig. 5. Panel a) Linear diattenuation spectra of Samples B (red), C (orange), D (green), E (blue) and F (purple). Panel b) Orientation of the diattenuation (transmission) axis of Sample F. Azimuths of 0° and 90° correspond to the lengthwise and crosswise directions of the composite film, respectively.
Figure 6 a) shows the wavelength dependence of linear retardance on the loading amount of AgNWs in Samples B – F. The retardance spectrum for all samples also shows a minimum value around 460–500 nm. Like linear diattenuation, retardance also increases with increasing loading amounts of AgNWs. Figure 6 b) shows the orientation of the fast axis of Sample F. Figure 6 b) indicates that the lengthwise direction coincides with the fast axis, which means refractive index of the lengthwise direction is lower than that of the crosswise direction.
Fig. 6. Panel a) Linear retardance spectra of Samples B (red), C (orange), D (green), E (blue) and F (purple). Panel b) Orientation of the fast axis of Sample F. Azimuths of 0° corresponds to the lengthwise directions of the composite film.
Using Mueller matrix ellipsometry, we determined in a previous work the orthogonal optical constants (complex refractive index; refractive index n and extinction coefficient k) and the effective thickness of the composite films [28]. Figure 7 shows the orthogonal optical constants of Sample B determined by same method. The dispersion curve of the refractive index is complex, due to the two AgNW extinction modes (transverse and longitudinal). Below 300 nm and above 400 nm, we observe the expected monotonic wavelength dependence of normal dispersion (n decreases with increasing wavelength). However, in the spectral range 300–400 nm, anomalous dispersion occurs (n increases with increasing wavelength). Because the AgNWs are preferentially oriented in the lengthwise direction of the composite film, kx is larger than ky in the longitudinal mode (above 450 nm). On the contrary, kx in the transverse mode (350–450 nm) is smaller than ky. Accordingly, the slope of nx is larger than those of ny above 450 nm, but slightly smaller between 400 – 450 nm. This behavior is due to the Kramers-Kronig relationship between k and n and likely explains the shape of the dispersion curve.
Fig. 7. Orthogonal optical constants of Sample B. The x, y and z axes are aligned with the lengthwise, crosswise and normal directions of the composite film, respectively. The solid lines represent the components of the refractive index along these axes (nx, blue; ny red; nz, green) and the dashed lines those of the extinction coefficient (kx, ky, kz, same color-coding).
Fig. 8. Comparison of the in-plane retardance of Sample B measured by ellipsometry (red dotted line) and polarimetry (blue solid line).
Figure 8 shows the comparison between the in-plane retardance of Sample B derived from ellipsometry ((ny - nx) multiplied by the effective thickness [28]) and polarimetry (Fig. 6) measurements. The retardance obtained by polarimetry are consistently larger (by 20–60%) than the results of the ellipsometry measurements. This ellipsometry analysis was conducted using multiple angles of incidence [28], whereas polarimetry measurements were taken under only one angle of incidence. As such, we estimate that the ellipsometry measurement data is more credible. However, both spectra show almost identical wavelength dependence. This expected shape is due to the impact of the normal and anomalous dispersion on the orthogonal component of the refractive index.
The third property we investigate is depolarization within the composite film. As explained in Section 2.2, depolarization is calculated from the parallel and crossed configuration transmittance measurements. Panels a) and b) of Fig. 9 show the transmittance of Sample F in polar coordinates, at 450 nm and 700 nm for the parallel (Panel a) and crossed (Panel b) configurations. During these measurements, Sample F is rotated by 360° and the transmittance measured every 5°.
Fig. 9. Polar representation of the transmittance of Sample F in the a) parallel and b) crossed configurations at 450 nm (blue curve) and 700 nm (red curve). Sample F is rotated by 360°. The measurement geometry is shown in the inset figures. Panels c) and d) show the transmission spectra at 0° and 45°, respectively, in the crossed configuration.
In the parallel condition (Fig. 9a), the transmittance curve at 450 nm has two, orthogonal lines of symmetry, with maximum values of the transmittance in the parallel direction (0–180°, lengthwise direction of the composite film) and minimum values in the perpendicular direction (90–270°, crosswise direction). The measurements at 700 nm also show two lines of symmetry in polar representation, but with the minimum in the parallel direction and the maximum in the perpendicular direction. In the crossed configuration, the transmittance curve shows four lobes, with the same orientation at 450 nm and 700 nm. Thus, there are four lines of symmetry, with minima in the parallel and perpendicular directions (0–180° and 90–270°) and maxima in the polar diagonal directions (45–225° and 135–315°). The fact that transmittance is smallest at 0° and 90° indicates that depolarization is the only effect observed in the lengthwise and crosswise direction of the composite film. The large transmittance in the intermediate directions (45° and 135°) is caused by depolarization and additional retardance effects. The transmission spectra at 0° and 45° for the crossed configuration measurements are shown in Panels c) and d) of Fig. 9, respectively. Figure 9 c) indicates that, in the lengthwise direction of the composite film (0°), transmittance is larger at shorter wavelengths due to the transverse mode extinction of the AgNWs, and decreases monotonically from a maximum value of ∼8.5 × 10−3% at ∼420 nm to about half (4 × 10−3%) at 780 nm. On the other hand, at 45° (Fig. 9 d), the transmittance spectrum has the same shape up to 500 nm (with transmittance values about 100 times larger) but transmittance increases again at longer wavelengths. This is likely due to additional retardance in the intermediate directions.
Finally, we investigate the impact of the sample properties (loading amount and diameter of the AgNWs) on depolarization within the composite films, as a function of the wavelength. The results for Samples B – F are summarized in Fig. 10 on panel a) for the loading amount and b) for the diameter of the AgNWs, respectively. The spectral dependence of the depolarization on the loading amount of AgNWs is similar to our findings for extinction (400–800 nm). As the loading amount of AgNWs increases, the depolarization within the composite film increases accordingly. This is expected, as a high density of AgNWs would naturally induce a high scattering of the incoming light, thus a large depolarization effect. The wavelength dependence of the calculated depolarization on the diameter of the AgNWs is shown in Fig. 10 b) for Samples A, B and G. As the diameter of the AgNWs decreases, depolarization within the composite film becomes significantly smaller, especially below 600 nm. We can therefore conclude that using small-diameter AgNWs is an effective solution to minimize the unwanted depolarization effects.
Fig. 10. Depolarization spectra of a) Samples B (red), C (orange), D (green), E (blue), and F (purple); b) Sample A (light blue), B (red) and G (black).
3.3 Light leakage in the case of crossed polarizers
In in-cell touch screens, the TCE is placed between crossed linear polarizers. Depolarization and retardance within the TCE deteriorate the contrast ratio of LCDs, because it causes light leakage when displaying a black image. Light leakage is the transmittance measured when the sample is placed between crossed linear polarizers. The impact of the composite film properties (loading amount and diameter of the AgNWs) on light leakage is shown in Fig. 11. Figure 11 a) shows the angular dependence of light leakage on the loading amount of the AgNWs for Samples B – F at 450 nm. Measurements are acquired close to the transmission axis of a linear polarizer, by rotating the optic axis of the sample. We vary the angular distance between the two axes (azimuthal angle) between -7.5° to + 7.5° by steps of 2.5°. We chose 450 nm as the example wavelength because the depolarization is larger at shorter wavelengths (as shown in Fig. 10). As the loading amount of the AgNWs increases, light leakage increases as well. Furthermore, we confirm here that light leakage is minimized if the optic axis of the composite film is aligned with the transmission axis of the polarizers. Figure 11 b) shows the dependence of light leakage on the diameter of the AgNWs in Samples A, B and G. As indicated above, the depolarization decreases with decreasing diameter of the AgNWs, thus minimizing the resulting light leakage. As shown in Fig. 11 b), the light leakage can be reduced to 7 × 10−4% by using AgNWs with a diameter of less than or equal to 23 nm in a composite film with a sheet resistance of 50Ω/sq. This is significantly less than the light leakage in a conventional film polarizer, which is about 5 × 10−3% [35].
Fig. 11. Light leakage (transmittance) of a) Samples B (red), C (orange), D (green), E (blue) and F (purple); b) Sample A (light blue), B (red) and G (black), in the crossed configuration. Measurements are acquired close to the transparent axis of a linear polarizer (azimuthal angle of 0°), by rotating the sample from -7.5° to + 7.5° by steps of 2.5°
4. Conclusions
Diattenuation, retardance and depolarization effects within silver nanowire/polymer composite films were measured and analyzed with spectroscopic polarimetry. Random scattering by AgNWs induces depolarization of the transmitted light, that we were able to quantify. We also characterized the linear diattenuation and retardance caused by the preferential orientation of AgNWs within the composite films. The measured amplitude of all three effects is directly proportional to the loading amount of AgNWs, but the depolarization decreases with the radius of the AgNWs. We believe that using composite films with a sheet resistance of about 50Ω/sq., and AgNWs similar to those of Sample B and G (average diameter of less than or equal to 23 nm) would allow us to reduce light leakage to about 7 × 10−4%. This is significantly less than a conventional film polarizer and small enough for practical use.
References
1. D. Langley, G. Giusti, C. Mayousse, C. Celle, D. Bellet, and J.-P. Simonato, “Flexible transparent conductive materials based on silver nanowire networks: a review,” Nanotechnology 24(45), 452001 (2013). [CrossRef]
2. S. Ye, A. R. Rathmell, Z. Chen, I. E. Stewart, and B. J. Wiley, “Metal Nanowire Networks: The Next Generation of Transparent Conductors,” Adv. Mater. 26(39), 6670–6687 (2014). [CrossRef]
3. J. Kwon, Y. D. Suh, J. Lee, P. Lee, S. Han, S. Hong, J. Yeo, H. Lee, and S. H. Ko, “Recent progress in silver nanowire based flexible/wearable optoelectronics,” J. Mater. Chem. C 6(28), 7445–7461 (2018). [CrossRef]
4. R. Zhang and M. Engholm, “Recent Progress on the Fabrication and Properties of Silver Nanowire-Based Transparent Electrodes,” Nanomaterials 8(8), 628 (2018). [CrossRef]
5. X. Xia, B. Yang, X. Zhang, and C. Zhou, “Enhanced film conductance of silver nanowire-based flexible transparent & conductive networks by bending,” Mater. Res. Express 2(7), 075009 (2015). [CrossRef]
6. H. Janga, D. Kim, H. Tak, J. Nam, and T.-i. Kim, “Ultra-mechanically stable and transparent conductive electrodes using transferred grid of Ag nanowires on flexible substrate,” Curr. Appl. Phys. 16(1), 24–30 (2016). [CrossRef]
7. P. Kou, L. Yang, C. Chang, and S. He, “Improved Flexible Transparent Conductive Electrodes based on Silver Nanowire Networks by a Simple Sunlight Illumination Approach,” Sci. Rep. 7(1), 42052 (2017). [CrossRef]
8. M. Spaid, “Wet-processable transparent conductive materials,” Inf. Disp. 28(1), 10–15 (2012). [CrossRef]
9. S. M. Bergin, Y.-H. Chen, A. R. Rathmell, P. Charbonneau, Z.-Y. Li, and B. J. Wiley, “The effect of nanowire length and diameter on the properties of transparent, conducting nanowire films,” Nanoscale 4(6), 1996–2004 (2012). [CrossRef]
10. R. M. Mutiso, M. C. Sherrott, A. R. Rathmell, B. J. Wiley, and K. I. Winey, “Integrating Simulations and Experiments To Predict Sheet Resistance and Optical Transmittance in Nanowire Films for Transparent Conductors,” ACS Nano 7(9), 7654–7663 (2013). [CrossRef]
11. M. Marus, A. Hubarevich, R. J. W. Lim, H. Huang, A. Smirnov, H. Wang, W. Fan, and X. W. Sun, “Effect of silver nanowire length in a broad range on optical and electrical properties as a transparent conductive film,” Opt. Mater. Express 7(3), 1105–1112 (2017). [CrossRef]
12. M. Jagota and N. Tansu, “Conductivity of Nanowire Arrays under Random and Ordered Orientation Configurations,” Sci. Rep. 5(1), 10219 (2015). [CrossRef]
13. T. Ackermann, R. Neuhaus, and S. Roth, “The effect of rod orientation on electrical anisotropy in silver nanowire networks for ultra-transparent electrodes,” Sci. Rep. 6(1), 34289 (2016). [CrossRef]
14. J. Dong and I. A. Goldthorpe, “Exploiting both optical and electrical anisotropy in nanowire electrodes for higher transparency,” Nanotechnology 29(4), 045705 (2018). [CrossRef]
15. G. Khanarian, J. Joo, X.-Q. Liu, P. Eastman, D. Werner, K. O’Connell, and P. Trefonas, “The optical and electrical properties of silver nanowire mesh films,” J. Appl. Phys. 114(2), 024302 (2013). [CrossRef]
16. C. Preston, Y. Xu, X. Han, J. N. Munday, and L. Hu, “Optical haze of transparent and conductive silver nanowire films,” Nano Res. 6(7), 461–468 (2013). [CrossRef]
17. T. Araki, J. Jiu, M. Nogi, H. Koga, S. Nagao, T. Sugahara, and K. Suganuma, “Low haze transparent electrodes and highly conducting air dried films with ultra-long silver nanowires synthesized by one-step polyol method,” Nano Res. 7(2), 236–245 (2014). [CrossRef]
18. X. Xu, S. He, C. Zhou, X. Xia, L. Xu, H. Chen, B. Yanga, and J. Yanga, “Largely-increased length of silver nanowires by controlled oxidative etching processes in solvothermal reaction and the application in highly transparent and conductive networks,” RSC Adv. 6(107), 105895 (2016). [CrossRef]
19. M. Marus, A. Hubarevich, W. J. Fan, H. Wang, A. Smirnov, K. Wang, H. Huang, and X. W. Sun, “Optical haze of randomly arranged silver nanowire transparent conductive films with wide range of nanowire diameters,” AIP Adv. 8(3), 035201 (2018). [CrossRef]
20. L. Kang, H. Chen, Z.-J. Yang, Y. Yuan, H. Huang, B. Yang, Y. Gao, and C. Zhou, “Seesaw-like polarized transmission behavior of silver nanowire arrays aligned by off-center spin-coating,” J. Appl. Phys. 123(20), 205110 (2018). [CrossRef]
21. J. Soni, H. Purwar, and N. Ghosh, “Quantitative polarimetry of plasmon resonant spheroidal metal nanoparticles: A Mueller matrix decomposition study,” Opt. Commun. 285(6), 1599–1607 (2012). [CrossRef]
22. Sayantan Ghosh, Jalpa Soni, Sudipta K. Bera, Ayan Banerjee, and Nirmalya Ghosh, “Mueller matrix polarimetry of plasmon resonant silver nano-rods: biomedical prospects,” Proc. SPIE.8699, 869902 (2013). [CrossRef]
23. S. Chandel, J. Soni, S. k. Ray, A. Das, A. Ghosh, S. Raj, and N. Ghosh, “Complete polarization characterization of single plasmonic nanoparticle enabled by a novel Dark-field Mueller matrix spectroscopy system,” Sci. Rep. 6(1), 26466 (2016). [CrossRef]
24. N. G. Khlebtsov, L. A. Trachuk, and A. G. Melnikov, “Plasmon resonances of silver and gold nanorods,” Proceedings of the SPIE.5475, 1–11 (2004).
25. N. G. Khlebtsov, “Anisotropic properties of plasmonic nanoparticles: depolarized light scattering, dichroism, and birefringence,” J. Nanophotonics 4(1), 041587 (2010). [CrossRef]
26. G. Walker and M. Fihn, “LCD In-Cell Touch,” Inf. Disp. 26(3), 8–14 (2010). [CrossRef]
27. Ranbir Singh, K.N. Narayanan Unni, Ankur Solanki, and Deepak, “Improving the contrast ratio of OLED displays: An analysis of various techniques,” Opt. Mater. 34(4), 716–723 (2012). [CrossRef]
28. T. Tomiyama and H. Yamazaki, “Optical anisotropy studies of silver nanowire/polymer composite films with Mueller matrix ellipsometry,” Appl. Surf. Sci. 421, 831–836 (2017). [CrossRef]
29. T. Tomiyama and H. Yasuhiro Seri, “Relationship between wire orientation and optical and electrical anisotropy in silver nanowire/polymer composite films,” Appl. Surf. Sci. 469, 340–347 (2019). [CrossRef]
30. S.-Y. Lu and R. A. Chipman, “” Interpretation of Mueller matrices based on polar decomposition”,” J. Opt. Soc. Am. A 13(5), 1106–1113 (1996). [CrossRef]
31. G. Toshima and T. Tomiyama, “A new touch-panel structure using metal mesh and Ag nanowire,” SID Int. Symp. Dig. Tech. Pap. 47(1), 308–310 (2016). [CrossRef]
32. Q. N. Luu, J. M. Doorn, M. T. Berry, C. Jiang, C. Lin, and P. Stanley May, “Preparation and optical properties of silver nanowires and silver-nanowire thin films,” J. Colloid Interface Sci. 356(1), 151–158 (2011). [CrossRef]
33. A. P. Bell, J. A. Fairfield, E. K. McCarthy, S. Mills, J. J. Boland, G. Baffou, and D. McCloskey, “Quantitative study of the photothermal properties of metallic nanowire networks,” ACS Nano 9(5), 5551–5558 (2015). [CrossRef]
34. B. Park, I.-G. Bae, and Y. H. Huh, “Aligned silver nanowire-based transparent electrodes for engineering polarisation-selective optoelectronics,” Sci. Rep. 6(1), 19485 (2016). [CrossRef]
35. Y. Utsumi, I. Hiyama, Y. Tomioka, K. Kondo, and S. Matsuyama, “Analysis of light leakage caused by color filter between crossed polarizers,” Jpn. J. Appl. Phys. 46(3A), 1047–1050 (2007). [CrossRef]
