Abstract

We demonstrate localized surface plasmon (LSP)-enhanced near-ultraviolet light-emitting diodes (NUV-LEDs) using silver (Ag) and platinum (Pt) nanoparticles (NPs). The optical output power of NUV-LEDs with metal NPs is higher by 20.1% for NUV-LEDs with Ag NPs and 57.9% for NUV-LEDs with Pt NPs at 20 mA than that of NUV-LEDs without metal NPs. The time-resolved photoluminescence (TR-PL) spectra shows that the decay times of NUV-LEDs with Ag and Pt NPs are faster than that of NUV-LEDs without metal NPs. The TR-PL and absorbance spectra of metal NPs indicate that the spontaneous emission rate is increased by resonance coupling between excitons in the multiple quantum wells and LSPs in the metal NPs.

© 2013 OSA

1. Introduction

Recently, near-ultraviolet (NUV) light-emitting diodes (LEDs) have been used in many applications such as light sources for photometric detecting systems, biochemical sensors, medical equipment, counterfeit bill detection, and pumping sources of white LEDs [15]. However, the internal quantum efficiency (IQE) of NUV-LEDs is much lower than those of blue and green LEDs [1, 6], because the NUV-LEDs have a reduced potential confinement of carriers due to the low indium (In) composition in InGaN quantum wells (QWs) compared with blue and green LEDs. Much research has been performed to improve the IQE of NUV-LEDs by improving crystal quality [710]. However, it is still necessary to investigate means to enhance the IQE for high efficiency NUV-LEDs.

It was reported that the efficiency of GaN-based blue and green LEDs can be enhanced by using localized surface plasmon (LSP) resonance in the visible region [11, 12]. Surface plasmons (SPs) are collective oscillations of free electrons in metals at the interfaces between metals and dielectric materials [13, 14]. In particular, the collective oscillations of electrons in metal nanoparticles (NPs) embedded in a dielectric material are LSPs. In LEDs with NPs, excitons in the QW can be affected by a resonant coupling to SP modes within the penetration depth of the SP fringing field. The spontaneous emission rate in QW can be enhanced by the influence of the local electric field from the SP mode [15]. Silver (Ag) and platinum (Pt) NPs have been reported to have SP characteristic wavelengths for blue and ultraviolet emission by photoluminescence (PL) and absorption measurements [11, 16]. However, investigations on the coupling between NUV emission of NUV-LEDs and LSPs in metal NPs have not been reported even though these are expected to improve the IQE of NUV-LEDs. In this study, we successfully demonstrated the LSP-enhanced NUV-LEDs using Ag and Pt NPs embedded in p-GaN layer. The NUV-LEDs with p-GaN containing either Ag or Pt showed good electrical properties and the increased optical output power. These results were attributed to an increase in IQE by LSPs resonance coupling between excitons in the multiple quantum wells (MQWs) and metal NPs in the p-GaN layer. Pt NPs showed more advantages over Ag NPs with respect to the particle density and the SP characteristic peak. The high density of Pt NPs, which can increase the penetration depth, could be easily achieved and a closer match between the SP characteristic wavelength of Pt NPs and an emission wavelength of NUV-LEDs was highly desirable for high efficiency NUV-LEDs.

2. Experiments

The NUV-LEDs were grown on a c-plane (0001) sapphire by metal-organic chemical vapor deposition (MOCVD). Figure 1(a) shows a schematic diagram of LSPs-enhanced NUV-LEDs with metal NPs. After the growth of a 25 nm-thick GaN nucleation layer at 550 °C, a 2 μm-thick undoped GaN layer and a 2 μm-thick Si-doped n-GaN layer were grown at 1020 °C. Then, five periods of InGaN/GaN NUV-MQWs consisting of 3 nm-undoped InGaN wells and 12 nm-Si doped GaN barriers were grown at 770 °C, followed by a 20 nm-thick p-GaN layer grown at 950 °C as a spacer layer between MQWs and metal NPs. To estimate the effective thickness of p-GaN spacer layer between MQWs and metal NPs layer, the penetration depth of the SP fringing field was first calculated from Z = (λ/2π)[(ε´GaN - ε´metal)/ε´metal2]1/2, where ε´GaN and ε´metal are the real part of the dielectric constants for GaN and metal, and λ is the wavelength of the SP resonance [13]. The penetration depth of SP fringing field for Ag and Pt was calculated as 41.0 and 38.9 nm for SP-QW coupling, respectively, at an NUV emission wavelength of 406 nm when the real parts of the dielectric constants for GaN and metal were used [17, 18]. However, Jang et al. showed that the penetration depth of Ag NPs surrounded by dielectric materials is estimated to be in the range of 8-18 nm with increasing the number of Ag NPs from single NP to 7 NPs [19]. In this study, the NUV-LEDs with metal NPs and a p-GaN spacer layer with a thickness of less than 10 nm showed a poor electrical performance presumably due to the rapid thermal annealing (RTA) process for metal NP formation and the subsequent overgrowth of 200 nm-thick p-GaN on metal NPs. To study the resonance coupling effect of LSPs and MQWs of NUV-LEDs with stable operation, a 20 nm-thick p-GaN was used as a spacer layer in this study. The Ag or Pt layer was deposited on the p-GaN spacer layer by e-beam evaporation and metal NPs were formed by RTA process. A p-GaN layer was overgrown on the metal NPs and metal NPs were embedded in the 200 nm-thick p-GaN layer. To fabricate NUV-LEDs, a dry etching process was performed until the n-GaN layer was exposed for n-type ohmic contact by an inductively-coupled plasma etching process using Cl2/CH4/H2/Ar source gases. Then, the NUV-LEDs, each of size 300 × 300 µm2, were fabricated by using 150 nm-thick indium tin oxide as a transparent current spreading layer and Cr (50 nm)/Au (150 nm) layers were deposited as n- and p-contact by e-beam evaporation. Figure 1(b) and 1(c) show scanning electron microscopy (SEM) images of metal NPs on the p-GaN spacer layer after the RTA process, performed at 600 °C for 5 min under an N2 ambient gas prior to the over-growth of the p-GaN layer on the metal NPs. The thin metal layer was transformed into NPs via the Ostwald ripening process. The diameter and density of Ag NPs are in the range of 35-75 nm and 2 × 109 cm−2, respectively, whereas those of Pt NPs are in the range of 10-40 nm and 4 × 1010 cm−2, respectively. The density of Pt NPs was always higher by ~20 times than Ag NPs on p-GaN layer under the same deposition and annealing conditions.

 

Fig. 1 (a) Schematic diagram of the LSP-enhanced NUV-LEDs with metal NPs in p-GaN layer. SEM images of (b) Ag NPs and (c) Pt NPs on the 20 nm-thick p-GaN spacer layer after a rapid thermal annealing process.

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3. Results and discussion

Figure 2(a) , 2(b), and 2(c) show the PL spectra at 10 K and 300 K of NUV-LEDs with and without metal NPs, respectively. The IQE of NUV-LEDs was estimated by comparing the integrated PL intensities, assuming that the IQE is 100% at 10 K [13]. The IQEs of NUV-LEDs with Ag, Pt, and without metal NPs are calculated to be 52.2%, 60.5% and 41.8%, respectively, and the IQEs of NUV-LEDs with Ag and Pt NPs are increased by 24.9% and 44.7%, respectively, compared with that of NUV-LEDs without metal NPs. It has been reported that the probability of coupling between the excitons in MQWs and LSPs increases with increasing density of metal NPs in the p-GaN layer [20]. The fact that the enhancement in IQE of NUV-LEDs with Pt NPs is higher than that of NUV-LEDs with Ag NPs is attributed partly to the particle density of Pt which is higher than that of Ag NPs. Figure 2(d) shows the PL enhancement ratio of the PL intensity of NUV-LEDs with metal NPs to that of NUV-LEDs without metal NPs. The inset of Fig. 2(d) shows the absorbance of metal NPs as a function of wavelength. As shown in the inset of Fig. 2(d), the peak position of absorbance of Pt NPs is closer to a 406 nm emission wavelength of NUV-LEDs compared with that of Ag NPs. The absorbance spectra of Pt NPs is much broader than that of Ag NPs due to the different nature of SPs in Pt and Ag nanostructures [21] and high density of Pt NPs. The high density of Pt NPs can also cause a large penetration depth in MQWs, resulting in a strong SP resonance with excitons in MQWs. For this reason, the PL enhancement ratio of NUV-LEDs with Pt NPs is higher than that of NUV-LEDs with Ag NPs as shown in Fig. 2(d) because the peak position of absorbance of Pt NPs, which represents the SP characteristic wavelength of Pt NPs is closer to the 406 nm emission wavelength of NUV-LEDs and the density of Pt NPs is higher than that of Ag NPs.

 

Fig. 2 PL spectra at 10 K and 300 K of the NUV-LEDs; (a) without metal NPs, (b) with Ag NPs, and (c) with Pt NPs. (d) PL enhancement ratio of PL intensity of the NUV-LEDs with Ag and Pt NPs to that of the NUV-LED without metal NPs. The inset shows the absorbance of Ag and Pt NPs as a function of wavelength.

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Figure 3 shows time-resolved PL (TR-PL) spectra of NUV-LEDs with and without metal NPs. The light source was a Ti:sapphire laser (MaiTai, Spectra Physics) with 100 fs pulse width, 710 nm wavelength, and repetition rate of 80 MHz, which was further reduced to 4.44 MHz using a pulse picker to obtain a temporal window as long as 200 ns. The beam was frequency doubled to 355 nm by using a β-BaB2O4 (BBO) crystal. The collected PL was dispersed by a 30-cm monochromator and detected by a streak scope (C10627, Hamamatsu K.K.) to obtain PL decay curves. The TR-PL measurement was performed at 10 K to remove non-radiative recombination process that competes with the LSPs coupling. The decay lifetime τ is defined such that the ideal radiative decay curve can be shown as I(t) = Ae-t/τ, where A is the normalization constant. The fast part of each decay curve is fitted with a monoexponential decay model to investigate the resonance coupling between excitons in the MQWs and LSPs of the metal NPs. The decay time of NUV-LEDs with Ag and Pt NPs is 3.77 ns and 3.68 ns, respectively, whereas that of NUV-LEDs without metal NPs is 4.26 ns. The faster decay time of NUV-LEDs with metal NPs can be attributed to resonance coupling between MQWs and LSPs. When the energy of the excitons in QW is close to the electron vibrational energy of the LSP in the metal NPs, the recombination rate of excitons can be increased via fast recombination path due to the energy transfer from excitons to LSPs [13, 14].

 

Fig. 3 Time resolved-PL spectra of the NUV-LEDs with and without metal NPs at 10 K. (a) without metal NPs, (b) with Ag NPs, and (c) with Pt NPs.Sample figure.

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Figure 4(a) shows the current-voltage (I-V) curves of NUV-LEDs with and without metal NPs. The forward voltages of NUV-LEDs with and without metal NPs are nearly the same as 3.9 V at 20 mA. Additionally, the series resistance of NUV-LEDs with Ag, Pt NPs, and without metal NPs is 16.1 Ω, 16.0 Ω, and 16.1 Ω, respectively. These results indicate that the electrical properties of NUV-LEDs with metal NPs are not degraded by the metal NPs embedded in p-GaN.

 

Fig. 4 (a) I-V curves of the NUV-LEDs with and without metal NPs. (b) Optical output power of the NUV-LEDs with and without metal NPs as a function of injection current.

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Figure 4(b) shows the optical output power of the NUV-LEDs with and without metal NPs as a function of injection current. The optical output power of the NUV-LEDs was measured at a distance of 5 cm from the top of the NUV-LEDs by Si photodiode. As shown in Fig. 4(b), the optical output power of the NUV-LEDs with metal NPs is higher than that of the NUV-LEDs without metal NPs. Compared with NUV-LEDs without metal NPs, the optical output power of NUV-LEDs with Ag and Pt NPs is increased by 20.1% and 57.9% at an injection current of 20 mA, respectively. The measurements of IQE and TR-PL of the NUV-LEDs show that the enhancement of optical output power is attributed to the increase in the spontaneous emission rate by resonance coupling between excitons in the MQWs and LSPs in the metal NPs.

4. Summary

In summary, we investigated the LSP-enhanced NUV-LEDs by using Ag or Pt NPs embedded in p-GaN layer. The optical output power of NUV-LEDs with metal NPs is increased by 20.1% for NUV-LEDs with Ag NPs and 57.9% for NUV-LEDs with Pt NPs at 20 mA compared with that of NUV-LEDs without metal NPs. The IQE of NUV-LEDs with metal NPs is increased by 24.9% for NUV-LEDs with Ag NPs and 44.7% for NUV-LEDs with Pt NPs compared with that of NUV-LEDs without metal NPs. The TR-PL measurement shows the PL decay time is decreased in NUV-LEDs with metal NPs embedded in p-GaN layer. These results indicate that the increase in optical output power of the NUV-LEDs with metal NPs is attributed to an increase in IQE by LSPs resonance coupling between excitons in the MQWs and metal NPs in the p-GaN layer. In addition, Pt NPs are found to be more suitable for LSP-enhanced NUV-LEDs due to the easy formation of high density NPs and a closer match between the SP characteristic wavelength of Pt NPs and an emission wavelength (406 nm) of NUV-LEDs, compared to Ag NPs.

Acknowledgments

This work was supported by Korea Science and Engineering Foundation (KOSEF) NCRC grant funded by the Korea government (MEST) (Project No. R15-2008-006-02001-0), the Samsung LED Research Center at GIST, and partially supported by APRI-Research Program through a grant provided by GIST.

References and links

1. T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth 189/190(158), 778–781 (1998). [CrossRef]  

2. Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett. 74(4), 558–560 (1999). [CrossRef]  

3. T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett. 81(14), 2508–2510 (2002). [CrossRef]  

4. P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature 406(6798), 865–868 (2000). [CrossRef]   [PubMed]  

5. Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng. 44(12), 124003 (2005). [CrossRef]  

6. T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett. 79(6), 711–712 (2001). [CrossRef]  

7. S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett. 83(24), 4906–4908 (2003). [CrossRef]  

8. C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth 315(1), 242–245 (2011). [CrossRef]  

9. M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi 4(7), 2822–2825 (2007) (c). [CrossRef]  

10. S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys. 110(12), 123102 (2011). [CrossRef]  

11. M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.) 20(7), 1253–1257 (2008). [CrossRef]  

12. C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett. 98(5), 051106 (2011). [CrossRef]  

13. K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater. 3(9), 601–605 (2004). [CrossRef]   [PubMed]  

14. K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett. 87(7), 071102 (2005). [CrossRef]  

15. A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B 66(15), 153305 (2002). [CrossRef]  

16. T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett. 95(11), 111112 (2009). [CrossRef]  

17. T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys. 82(7), 3528 (1997). [CrossRef]  

18. D. R. Lide ed., CRC Handbook of Chemistry and Physics, 90th ed. (CRC Press, 2010).

19. L. W. Jang, D. W. Jeon, T. Sahoo, D. S. Jo, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, J. H. Song, A. Y. Polyakov, and I. H. Lee, “Localized surface plasmon enhanced quantum efficiency of InGaN/GaN quantum wells by Ag/SiO2 nanoparticles,” Opt. Express 20(3), 2116–2123 (2012). [CrossRef]   [PubMed]  

20. C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology 21(20), 205201 (2010). [CrossRef]   [PubMed]  

21. C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett. 6(4), 833–838 (2006). [CrossRef]   [PubMed]  

References

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  1. T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
    [CrossRef]
  2. Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
    [CrossRef]
  3. T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
    [CrossRef]
  4. P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
    [CrossRef] [PubMed]
  5. Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng.44(12), 124003 (2005).
    [CrossRef]
  6. T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
    [CrossRef]
  7. S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
    [CrossRef]
  8. C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
    [CrossRef]
  9. M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
    [CrossRef]
  10. S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
    [CrossRef]
  11. M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
    [CrossRef]
  12. C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
    [CrossRef]
  13. K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
    [CrossRef] [PubMed]
  14. K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
    [CrossRef]
  15. A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
    [CrossRef]
  16. T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
    [CrossRef]
  17. T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
    [CrossRef]
  18. D. R. Lide ed., CRC Handbook of Chemistry and Physics, 90th ed. (CRC Press, 2010).
  19. L. W. Jang, D. W. Jeon, T. Sahoo, D. S. Jo, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, J. H. Song, A. Y. Polyakov, and I. H. Lee, “Localized surface plasmon enhanced quantum efficiency of InGaN/GaN quantum wells by Ag/SiO2 nanoparticles,” Opt. Express20(3), 2116–2123 (2012).
    [CrossRef] [PubMed]
  20. C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
    [CrossRef] [PubMed]
  21. C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
    [CrossRef] [PubMed]

2012

2011

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

2010

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

2009

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

2008

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

2007

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

2006

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

2005

Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng.44(12), 124003 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

2004

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

2003

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

2002

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

2001

T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
[CrossRef]

2000

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

1999

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

1998

T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
[CrossRef]

1997

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Adach, S.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Ao, J. P.

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

Baek, J. H.

Bai, J.

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

Brandt, O.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Byeon, C. C.

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Chiu, C. H.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Cho, C. Y.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Cho, Y. H.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

Everitt, H. O.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Fujita, S.

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

Fuke, S.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Grahn, H. T.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Han, S. H.

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Hong, S. H.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

Horng, R. H.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Huang, S. C.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Jang, L. W.

Jeon, D. W.

Jeong, H.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Jo, D. S.

Ju, J. W.

Kang, J. W.

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Kang, S. E.

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Kasemo, B.

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

Kaufmann, U.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Kawakami, Y.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

Kawashima, T.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Ke, C. C.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Kim, B. H.

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Kim, H.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Kim, J. D.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Kim, J. Y.

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Kobayashi, N.

T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
[CrossRef]

Kohler, K.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Kudo, H.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Kunzer, M.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Kuo, H. C.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Kuroda, T.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Kwon, M. K.

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Langhammer, C.

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

Leancu, C. C.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Lee, C. W.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Lee, D. Y.

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Lee, I. H.

Lee, K. J.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Lee, S. J.

L. W. Jang, D. W. Jeon, T. Sahoo, D. S. Jo, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, J. H. Song, A. Y. Polyakov, and I. H. Lee, “Localized surface plasmon enhanced quantum efficiency of InGaN/GaN quantum wells by Ag/SiO2 nanoparticles,” Opt. Express20(3), 2116–2123 (2012).
[CrossRef] [PubMed]

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Lee, S. M.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

Lee, Y. H.

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

Lee, Y. S.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Li, J. C.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Liu, S.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Lu, T. C.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Menniger, J.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Morita, D.

T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
[CrossRef]

Mukai, T.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
[CrossRef]

Nagashima, M.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Nakamura, S.

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
[CrossRef]

Narukawa, Y.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

Neogi, A.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Niki, I.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Nishida, T.

T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
[CrossRef]

Oh, T. S.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Ohtsuka, K.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Okagawa, H.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Okamoto, K.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Park, A. H.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Park, I. K.

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Park, S. J.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Ploog, K. H.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Polyakov, A. Y.

Ramsteiner, M.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Reiche, M.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Sahoo, T.

Saijou, S.

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

Saito, H.

T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
[CrossRef]

Sakai, S.

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

Sasaki, C.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Scherer, A.

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Seo, T. H.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Shen, K. C.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Shvartser, A.

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Song, J. H.

L. W. Jang, D. W. Jeon, T. Sahoo, D. S. Jo, J. W. Ju, S. J. Lee, J. H. Baek, J. K. Yang, J. H. Song, A. Y. Polyakov, and I. H. Lee, “Localized surface plasmon enhanced quantum efficiency of InGaN/GaN quantum wells by Ag/SiO2 nanoparticles,” Opt. Express20(3), 2116–2123 (2012).
[CrossRef] [PubMed]

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

Suh, E. K.

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Tackeuchi, A.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Tadatomo, K.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Taguchi, T.

Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng.44(12), 124003 (2005).
[CrossRef]

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Trampert, A.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Tu, C. C.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Tu, P. M.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Uchida, Y.

Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng.44(12), 124003 (2005).
[CrossRef]

Ueki, Y.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Wagner, J.

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Waltereit, P.

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Wang, C. H.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Wang, S. C.

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Wang, T.

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

Watanabe, S.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Wuu, D. S.

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

Yablonovitch, E.

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Yamada, N.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Yamada, Y.

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

Yang, J. K.

Yoshikawa, H.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

Yuan, Z.

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

Zoric, I.

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

Adv. Mater. (Deerfield Beach Fla.)

M. K. Kwon, J. Y. Kim, B. H. Kim, I. K. Park, C. Y. Cho, C. C. Byeon, and S. J. Park, “Surface-plasmon-enhanced light-emitting diodes,” Adv. Mater. (Deerfield Beach Fla.)20(7), 1253–1257 (2008).
[CrossRef]

Appl. Phys. Lett.

C. Y. Cho, S. J. Lee, J. H. Song, S. H. Hong, S. M. Lee, Y. H. Cho, and S. J. Park, “Enhanced optical output power of green light-emitting diodes by surface plasmon of gold nanoparticles,” Appl. Phys. Lett.98(5), 051106 (2011).
[CrossRef]

K. Okamoto, I. Niki, A. Scherer, Y. Narukawa, T. Mukai, and Y. Kawakami, “Surface plasmon enhanced spontaneous emission rate of InGaN/GaN quantum wells probed by time-resolved photoluminescence spectroscopy,” Appl. Phys. Lett.87(7), 071102 (2005).
[CrossRef]

T. S. Oh, H. Jeong, Y. S. Lee, J. D. Kim, T. H. Seo, H. Kim, A. H. Park, K. J. Lee, and E. K. Suh, “Coupling of InGaN/GaN multiquantum-wells photoluminescence to surface plasmons in platinum nanocluster,” Appl. Phys. Lett.95(11), 111112 (2009).
[CrossRef]

Y. Narukawa, S. Saijou, Y. Kawakami, S. Fujita, T. Mukai, and S. Nakamura, “Radiative and nonradiative recombination processes in ultraviolet light-emitting diode composed of In0.02Ga0.98N active layer,” Appl. Phys. Lett.74(4), 558–560 (1999).
[CrossRef]

T. Wang, Y. H. Lee, J. P. Ao, J. Bai, and S. Sakai, “1 mW AlInGaN-based ultraviolet light-emitting diode with an emission wavelength of 348 nm grown on sapphire substrate,” Appl. Phys. Lett.81(14), 2508–2510 (2002).
[CrossRef]

T. Nishida, H. Saito, and N. Kobayashi, “Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN,” Appl. Phys. Lett.79(6), 711–712 (2001).
[CrossRef]

S. Watanabe, N. Yamada, M. Nagashima, Y. Ueki, C. Sasaki, Y. Yamada, T. Taguchi, K. Tadatomo, H. Okagawa, and H. Kudo, “Internal quantum efficiency of highly-efficient InxGa1-xN-based near-ultraviolet light-emitting diodes,” Appl. Phys. Lett.83(24), 4906–4908 (2003).
[CrossRef]

J. Appl. Phys.

T. Kawashima, H. Yoshikawa, S. Adach, S. Fuke, and K. Ohtsuka, “Optical properties of hexagonal GaN,” J. Appl. Phys.82(7), 3528 (1997).
[CrossRef]

S. C. Huang, K. C. Shen, D. S. Wuu, P. M. Tu, H. C. Kuo, C. C. Tu, and R. H. Horng, “Study of 375nm ultraviolet InGaN/AlGaN light-emitting diodes with heavily Si-doped GaN transition layer in growth mode, internal quantum efficiency, and device performance,” J. Appl. Phys.110(12), 123102 (2011).
[CrossRef]

J. Cryst. Growth

T. Mukai, D. Morita, and S. Nakamura, “High-power UV InGaN/AlGaN double-heterostructure LEDs,” J. Cryst. Growth189/190(158), 778–781 (1998).
[CrossRef]

C. H. Wang, C. C. Ke, C. H. Chiu, J. C. Li, H. C. Kuo, T. C. Lu, and S. C. Wang, “Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method,” J. Cryst. Growth315(1), 242–245 (2011).
[CrossRef]

Nano Lett.

C. Langhammer, Z. Yuan, I. Zorić, and B. Kasemo, “Plasmonic properties of supported Pt and Pd nanostructures,” Nano Lett.6(4), 833–838 (2006).
[CrossRef] [PubMed]

Nanotechnology

C. Y. Cho, M. K. Kwon, S. J. Lee, S. H. Han, J. W. Kang, S. E. Kang, D. Y. Lee, and S. J. Park, “Surface plasmon-enhanced light-emitting diodes using silver nanoparticles embedded in p-GaN,” Nanotechnology21(20), 205201 (2010).
[CrossRef] [PubMed]

Nat. Mater.

K. Okamoto, I. Niki, A. Shvartser, Y. Narukawa, T. Mukai, and A. Scherer, “Surface-plasmon-enhanced light emitters based on InGaN quantum wells,” Nat. Mater.3(9), 601–605 (2004).
[CrossRef] [PubMed]

Nature

P. Waltereit, O. Brandt, A. Trampert, H. T. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, and K. H. Ploog, “Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes,” Nature406(6798), 865–868 (2000).
[CrossRef] [PubMed]

Opt. Eng.

Y. Uchida and T. Taguchi, “Lighting theory and luminous characteristics of white light-emitting diodes,” Opt. Eng.44(12), 124003 (2005).
[CrossRef]

Opt. Express

Phys. Rev. B

A. Neogi, C. W. Lee, H. O. Everitt, T. Kuroda, A. Tackeuchi, and E. Yablonovitch, “Enhancement of spontaneous recombination rate in a quantum well by resonant surface plasmon coupling,” Phys. Rev. B66(15), 153305 (2002).
[CrossRef]

Phys. Status Solidi

M. Kunzer, U. Kaufmann, K. Kohler, C. C. Leancu, S. Liu, and J. Wagner, “Near-UV to violet LEDs - wavelength dependence of efficiency limiting processes,” Phys. Status Solidi4(7), 2822–2825 (2007) (c).
[CrossRef]

Other

D. R. Lide ed., CRC Handbook of Chemistry and Physics, 90th ed. (CRC Press, 2010).

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Figures (4)

Fig. 1
Fig. 1

(a) Schematic diagram of the LSP-enhanced NUV-LEDs with metal NPs in p-GaN layer. SEM images of (b) Ag NPs and (c) Pt NPs on the 20 nm-thick p-GaN spacer layer after a rapid thermal annealing process.

Fig. 2
Fig. 2

PL spectra at 10 K and 300 K of the NUV-LEDs; (a) without metal NPs, (b) with Ag NPs, and (c) with Pt NPs. (d) PL enhancement ratio of PL intensity of the NUV-LEDs with Ag and Pt NPs to that of the NUV-LED without metal NPs. The inset shows the absorbance of Ag and Pt NPs as a function of wavelength.

Fig. 3
Fig. 3

Time resolved-PL spectra of the NUV-LEDs with and without metal NPs at 10 K. (a) without metal NPs, (b) with Ag NPs, and (c) with Pt NPs.Sample figure.

Fig. 4
Fig. 4

(a) I-V curves of the NUV-LEDs with and without metal NPs. (b) Optical output power of the NUV-LEDs with and without metal NPs as a function of injection current.

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