Abstract

SiNx-based photonic crystal (PhC) patterns were fabricated on the ITO electrode layer of a GaN-based light-emitting diode (LED) device on a patterned sapphire substrate (PSS) by a UV nanoimprint lithography process in order to improve the light extraction of the device. A three-dimensional finite-difference time-domain simulation confirmed that the light extraction of a GaN LED structure on a PSS is enhanced when SiNx PhC patterns are formed on the ITO top layer. From the I-V characteristics, the electrical properties of patterned LED devices with SiNx-based PhC were not degraded compared to the unpatterned LED device, since plasma etching of the p-GaN or the ITO layers was not involved in the patterning process. Additionally, the patterned LED devices with SiNx-based PhCs showed 19%-increased electroluminescence intensity compared with the unpatterned LED device at 445 nm wavelength when a 20 mA current is driven.

© 2012 OSA

1. Introduction

GaN-based light-emitting diodes (LEDs) have recently attracted significant attention for their diverse applications, such as backlighting in liquid crystal displays, traffic signal lamps, vehicle lamps and general illumination both indoors and outdoors. However, the external quantum efficiency of GaN-based LEDs is still not high enough to realize LED-based solid state lighting. The external quantum efficiency is mainly limited by low light extraction efficiency. One of the primary reasons for low light extraction efficiency is total internal reflection at the interface between a LED device and air, which is originated from the large difference in refractive index between GaN and air. By Snell’s law, the critical angle for a photon to escape from the device into air is about 24°, thus, a photon which propagates at an angle greater than the critical angle is guided and trapped inside the GaN-based LED device and is converted to heat, which degrades the performance and the durability of the device. Therefore, the enhancement of the light extraction is a crucial issue in improving the external quantum efficiency. To enhance the light extraction efficiency of GaN-based LEDs, various approaches, including the use of photonic crystals with large index contrast [13], microlens arrays [46], and self-assembled patterning [7] have been intensively conducted. The approach to address light extraction issue remains very important for achieving large external quantum efficiency in in GaN-based LEDs. In addition to the light extraction issue, it is important to note that achieving high internal quantum efficiency is also important for realizing InGaN-based LEDs with high external quantum efficiency. The charge separation issue has been an important limiting factor in achieving high internal quantum efficiency in InGaN quantum well (QW) LEDs [814], especially for longer wavelength emission and high operating current density. Recent works for achieving high internal quantum efficiency in InGaN QW LEDs by charge separation suppression include semi/non-polar InGaN QW [8,9], c-plane InGaN QW with large overlap design [1012], surface plasmon coupled InGaN QWs [13,14] approaches.

Especially, further enhancement of the external quantum efficiency of GaN-based LEDs on patterned sapphire substrates (PSSs) is greatly required. Most high quality GaN-based LEDs are fabricated on PSS in the current LED industry since the threading dislocation density in the epitaxial GaN layer is effectively reduced by the epitaxial lateral overgrowth and the micron-scaled patterns on the PSS act as scattering centers for the guided light inside LED devices [1519]. The use of PSSs with micron-sized dimensions has led to increased in light extraction efficiency in GaN-based LEDs. Recently, Lin and associates had demonstrated that there exists a dependency on the pattern coverage density on extraction efficiency enhancement for GaN LEDs grown on the micron-sized PSSs [20]. However, it is important to note that recent works by using nanoscale PSSs had also led to increase in internal quantum efficiency and light extraction efficiency in InGaN-based LEDs [2124], as a result of two order-of-magnitude reduction in threading dislocation [21], reduction in screw dislocation density [22], and increase in light scattering by nano-scaled pattern [23,24]. Although both the internal quantum efficiency and light extraction efficiency of GaN-based LEDs are enhanced by the PSS, a further increase of the light extraction is essential for the realization of high brightness and high efficiency LEDs.

In this study, SiNx-based photonic crystal (PhC) structures are formed on the GaN-based LEDs, fabricated on the PSS, in order to increase the external quantum efficiency by nanoimprint lithography (NIL) [2529], which offers low cost and high throughput compared to other lithography techniques such as photolithography [30], e-beam lithography [31] and so on. Prior to the NIL process, we analyzed the effect of the presence of the SiNx-based PhC on the light extraction of a GaN LED structure on a PSS using a three-dimensional finite-difference time-domain (FDTD) simulation tool. In addition, the optical and electrical properties of the patterned LED devices with SiNx-based PhC were confirmed by the electroluminescence (EL) and the I-V characteristics.

2. Experimental details

A typical GaN-based blue LED structure was grown on a (0001)-oriented PSS by a conventional MOCVD process. After the deposition of a thin low-temperature GaN buffer layer, the LED structure, which consists of layers of 5 µm thick un-doped GaN, 3 µm thick n-GaN, 50 nm thick InGaN/GaN multi QWs and 150 nm thick p-GaN, was fabricated. Then, a 200 nm thick ITO layer was sputtered onto the p-GaN layer to achieve current spreading between the p-pad metal and the p-GaN layer.

Figure 1 shows the overall patterning process for the fabrication of the SiNx-based PhC pattern on the LED structure. First, SiO2/SiNx was deposited on the ITO layer by a PECVD process. The thickness of the SiO2 layer was about 70 nm and the thickness of the SiNx layers was split between 300 nm and 500 nm in order to fabricate PhC patterns with different heights. After the PECVD process, a 200 nm thick LOL 2000TM sacrificial polymer layer was coated on the SiNx layer, followed by a UV NIL process at 20 atm of pressure while exposing the stack of the mold/resin/LED wafer to UV for 10 min. In the UV NIL process, a flexible polymer-based mold was used for conformal contact with the LED wafer [32]. A UV-curable resin composed of 65 wt% of benzylmethacrylate base monomer, 5 wt % of IrgacureTM 184 UV initiator and 30 wt% of methacryloxypropyl-terminated polydimethylsiloxanes, was used for the UV NIL to elevate the etch resistance to the oxygen plasma [33]. After the UV NIL process, the sacrificial polymer layer under the imprinted pattern was cleared off with an oxygen plasma treatment. Next, a 50 nm thick Cr layer was deposited by e-beam evaporation and was lifted off the SiNx layer by removing the pattern, which was composed of the imprint resin/polymer sacrificial layer, with dimethylformamide solution. Finally, the masked SiNx layer with the Cr pattern was etched by a reactive ion etching process using CF4 plasma and then the SiNx-based PhC patterns were formed on the LED structure.

 

Fig. 1 The fabrication process of the patterned LED device with SiNx-based PhCs on the ITO electrode of the GaN-based LED by using NIL and reactive ion etching processes.

Download Full Size | PPT Slide | PDF

To fabricate LED devices, at first, a photo-resist was coated onto the patterned LED wafer and was partially removed by photolithography to establish the contact region for p- and n-GaN. Prior to mesa etching, SiNx-based PhC patterns on the contact region for p- and n-GaN, which is not covered with the photo-resist, were removed along with the underlying SiO2 layer by dipping the sample in buffered oxide etcher solution. Through mesa etching using ICP and deposition of p- and n-pad metals, composed of Cr/Au, 300 µm x 300 µm conventional lateral-type LED devices were fabricated. To analyze the optical and electrical properties of the patterned LED devices, measurements of EL and I-V characteristics were conducted. A three-dimensional FDTD simulation on light extraction of the patterned LED structures was carried out using a commercially available FullWAVETM simulator [3436].

3. Results and discussion

In Fig. 2 , SiNx-based PhC patterns with heights of 300 nm and 500 nm, fabricated by the NIL and RIE processes, are shown. Figures 2(a) to 2(c) and Figs. 2(d) to 2(f) are SEM images of the cross-sectional, tilted and top views of PhC patterns with heights of 300 nm and 500 nm, respectively. Each well-aligned PhC pattern on the ITO electrode layer has a diameter of 250 nm and a pitch of 600 nm. Due to the difference of the etch resistance to CF4 plasma between the SiO2 and the SiNx layers, PhC patterns slightly display re-entrance etch-profiles. In this work, the etch rates of SiO2 and SiNx layers, deposited by PECVD, were about 25 nm/min and 50 nm/min, respectively. This re-entrance profile is clearer in the PhC pattern of 500 nm in height than the PhC pattern of 300 nm in height. Figure 3(a) is the top SEM image of the fabricated LED device with the SiNx PhC pattern. The SiNx PhC pattern was only formed on the ITO top electrode layer of the LED device. Thus, there is no problem in forming the p- and n-pad metals on the p-GaN and n-GaN, respectively. Figure 3(b) is the cross-sectional SEM image of the GaN-based LED structure with the SiNx PhC pattern, which was grown on the PSS with a diameter of 2.5 µm and a height of 1.5 µm. As shown in Fig. 3(b), the array of SiNx PhC patterns was uniformly fabricated on the ITO electrode layer of the GaN-based LED.

 

Fig. 2 (a)–(c) are cross sectional, tilted and top views of SEM micrographs of 300 nm-high SiNx PhC patterns on the ITO electrode, respectively. (d)–(f) are also cross sectional, tilted and top views of SEM micrographs of 500 nm-high SiNx PhC patterns on the ITO electrode, respectively.

Download Full Size | PPT Slide | PDF

 

Fig. 3 (a) Top and (b) cross sectional SEM images of the LED device with the SiNx PhC pattern.

Download Full Size | PPT Slide | PDF

To investigate the effect of the presence of the SiNx-based PhC patterns with different heights on the light extraction of LED structures, a three-dimensional FDTD simulation was conducted. Figures 4(a) to 4(c) are schematic diagrams of the simplified LED structures for the FDTD simulation, which are composed of a 200 nm thick ITO, a 9 µm thick GaN and 2 µm thick sapphire layers. The plane of continuous polarized dipoles was placed at 150 nm below the GaN surface as the light source which emits photons in random directions and the wavelength of the light source was set to 450 nm. The area of the simulation domain is limited to 3 µm x 5.1 µm and only the 300 nm-thick sapphire layer was partially involved in the simulation domain, in order to avoid the FDTD calculation being hugely time consuming. Three different LED structures, consisting of an LED on a flat sapphire substrate, an LED on PSS and an SiNx-PhC patterned LED on PSS, were considered as shown in Figs. 4(a) to 4(c). The lens-shaped PSS pattern in the simulation structure has a 2 µm diameter, 3 µm pitch and 1 µm height and is pseudo-hexagonally arrayed. The SiNx-PhC pattern in the simulation structure has a 300 nm diameter and 600 nm pitch and its height is split into levels from 100 nm to 900 nm with an increment of 200 nm. The grid size of the FDTD was set to 10 nm for reliable simulation computation, and periodic boundary conditions were applied to the x-y plane in order to minimize the effect of the small size of the simulation domain.

 

Fig. 4 Simplified FDTD simulation designs of (a) the conventional LED, (b) the LED with the PSS and (c) the LED with SiNx-PhC patterns and the PSS.

Download Full Size | PPT Slide | PDF

Figure 5 presents the results of the FDTD simulation for the considered LED structures, which are described in Fig. 4. By inserting the PSS into the normal LED structure, the light extraction efficiency was increased by 18.75%. This agrees well with lots of reports that a PSS is helpful in enhancing the light extraction of LEDs, as well as improving the crystal quality of GaN by reducing the threading dislocation density. When the SiNx-based PhC pattern with 300 nm of height is formed on the ITO top layer of the GaN LED structure, the light extraction efficiency was increased by up to 14.80%. Thus, from the simulation result, we confirmed further enhancement in the light extraction of a GaN-based LED on a PSS by introducing the additional patterned layer. This simulation method did not take into account the photon recycling and reabsorption process, thus this method may not provide the accurate absolute value of the light extraction efficiency. However, the use of this method is sufficient for providing comparison of the light extraction efficiency among all the LEDs.

 

Fig. 5 FDTD simulation results on light extraction of the conventional LED, the LED on the PSS and the SiNx-PhC patterned LED.

Download Full Size | PPT Slide | PDF

We measured the I-V characteristics of the unpatterned and SiNx-based PhC patterned LED devices, which were all fabricated on the PSS, as shown in Fig. 6 . The forward voltages of all LED devices are in the 4.1 V to 4.2 V range at 20 mA drive current. The inset in Fig. 6 shows that the I-V characteristics of the patterned LEDs exhibited reduction in leakage current, in comparison to that of the unpatterned LED. This result can be explained by the presence of the thin SiO2 layer on the ITO electrode, which acts as a surface passivation layer to prevent surface leakage [37, 38]. Thus, the electrical properties of the patterned LED devices with SiNx-based PhC were not degraded since no plasma etching process was conducted in the p-GaN layer while fabricating the SiNx-based PhC pattern on the ITO electrode.

 

Fig. 6 The I-V characteristics of the un-patterned LED device and LED devices with SiNx-PhC patterns of 300 nm and 500 nm in height. All LED devices were fabricated on the PSS. The inset shows the I-V characteristics on a logarithmic scale.

Download Full Size | PPT Slide | PDF

In order to confirm the effect of the presence of SiNx PhC pattern on the light extraction of the LED device, which was fabricated on the PSS, we measured the EL intensities of the unpatterned LED device and the patterned LED devices with SiNx PhC patterns, as shown in Fig. 7 . When 20 mA of current is injected, the EL intensities of the LED devices with SiNx-based PhC patterns of 300 nm and 500 nm in height were increased by 14.5% and 19%, respectively, compared to that of the unpatterned LED device at a wavelength of 445 nm, as shown in Fig. 7(a). In contrast to the simulation results, the LED device with the 300 nm-high SiNx-based PhC pattern showed stronger EL intensity than the LED device with the 500 nm-high SiNx-based PhC pattern. The different tendencies shown by the EL and the simulation might result from slight differences in structure between the fabricated SiNx-based PhC pattern and the designed SiNx-PhC pattern in the simulation, including the diameter and profile. So far, most studies on the light extraction of LEDs have been performed on LEDs with flat sapphire substrates. Enhancing the light extraction of LEDs on PSS is relatively more difficult than it is for LEDs on flat sapphire substrates since the light extraction efficiency is already enhanced by the PSS. However, further increase in the light extraction of the LED device on the PSS was confirmed by forming the SiNx-based PhC patterns, which suppress the total internal reflection. The EL intensity according to injection current at a wavelength of 445 nm is shown in Fig. 7(b). At every injection current, the patterned LED devices with SiNx-based PhCs showed higher EL intensity than the unpatterned LED device.

 

Fig. 7 (a) EL intensity at 20 mA current and (b) EL intensity versus injection current at a wavelength of 445 nm for the un-patterned LED device and the patterned LED devices with SiNx-based PhCs.

Download Full Size | PPT Slide | PDF

4. Conclusion

SiNx-based PhC patterns were formed on GaN-based LED devices fabricated on PSS by the UV-NIL process in order to enhance the light extraction efficiency. From the three-dimensional FDTD simulation, when the height of the SiNx-pattern is 300 nm, the light extraction efficiency of the SiNx-PhC patterned LED structure on the PSS was increased by up to 14.80% compared to the unpatterned LED structure on the PSS. Similar to the simulation results, the SiNx-based PhC patterned LED device on the PSS showed an increase in EL intensity of up to 19% compared to an unpatterned LED device on the PSS at 20 mA drive current. Thus, total internal reflection was suppressed inside the GaN-based LED device by inserting SiNx-based PhC patterns. Moreover, the electrical properties of all patterned LED devices were not degraded because plasma etching of the p-GaN layer was not performed in the patterning process.

Acknowledgments

This research was supported by the R&D program for Industrial Core Technology through the Korea Evaluation Institute of Industrial Technology supported by the Ministry of Knowledge Economy in Korea (Grant No. 10040225). This research was also supported by Technology Innovation Program funded by the Ministry of Knowledge Economy (20103020010020-11-2-100).

References and links

1. J. J. Wierer Jr, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009). [CrossRef]  

2. E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011). [CrossRef]  

3. E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011). [CrossRef]  

4. X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011). [CrossRef]  

5. D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005). [CrossRef]  

6. M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005). [CrossRef]  

7. S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011). [CrossRef]  

8. R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012). [CrossRef]  

9. R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011). [CrossRef]  

10. H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011). [CrossRef]   [PubMed]  

11. J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011). [CrossRef]  

12. L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012). [CrossRef]  

13. H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011). [CrossRef]  

14. C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011). [CrossRef]  

15. Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006). [CrossRef]  

16. D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006). [CrossRef]  

17. Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004). [CrossRef]  

18. X.-H. Huang, J.-P. Liu, J.-J. Kong, H. Yang, and H.-B. Wang, “High-efficiency InGaN-based LEDs grown on patterned sapphire substrates,” Opt. Express 19(S4Suppl 4), A949–A955 (2011). [CrossRef]   [PubMed]  

19. K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001). [CrossRef]  

20. H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012). [CrossRef]  

21. Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011). [CrossRef]  

22. W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011). [CrossRef]  

23. C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010). [CrossRef]  

24. T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010). [CrossRef]  

25. K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007). [CrossRef]  

26. L. J. Guo, “Recent progress in nanoimprint technology and its applications,” J. Phys. D Appl. Phys. 37(11), R123–R141 (2004). [CrossRef]  

27. F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006). [CrossRef]   [PubMed]  

28. H. K. Cho, J. Jang, J.-H. Choi, J. Choi, J. Kim, J. S. Lee, B. Lee, Y. H. Choe, K.-D. Lee, S. H. Kim, K. Lee, S.-K. Kim, and Y.-H. Lee, “Light extraction enhancement from nano-imprinted photonic crystal GaN-based blue light-emitting diodes,” Opt. Express 14(19), 8654–8660 (2006). [CrossRef]   [PubMed]  

29. T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009). [CrossRef]  

30. M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001). [CrossRef]  

31. M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004). [CrossRef]  

32. K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011). [CrossRef]  

33. S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009). [CrossRef]  

34. FullWAVE 6.1, Rsoft Design Group, Inc., http://www.rsoftdesign.com

35. C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007). [CrossRef]  

36. K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011). [CrossRef]  

37. S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003). [CrossRef]  

38. Y. Z. Chiou, “Leakage current analysis of nitride-based photodetectors by emission microscopy inspection,” IEEE Sens. J. 8(9), 1506–1510 (2008). [CrossRef]  

References

  • View by:
  • |
  • |
  • |

  1. J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
    [CrossRef]
  2. E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
    [CrossRef]
  3. E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
    [CrossRef]
  4. X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
    [CrossRef]
  5. D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
    [CrossRef]
  6. M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
    [CrossRef]
  7. S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
    [CrossRef]
  8. R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
    [CrossRef]
  9. R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
    [CrossRef]
  10. H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
    [CrossRef] [PubMed]
  11. J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011).
    [CrossRef]
  12. L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
    [CrossRef]
  13. H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
    [CrossRef]
  14. C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
    [CrossRef]
  15. Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
    [CrossRef]
  16. D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
    [CrossRef]
  17. Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
    [CrossRef]
  18. X.-H. Huang, J.-P. Liu, J.-J. Kong, H. Yang, and H.-B. Wang, “High-efficiency InGaN-based LEDs grown on patterned sapphire substrates,” Opt. Express 19(S4Suppl 4), A949–A955 (2011).
    [CrossRef] [PubMed]
  19. K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
    [CrossRef]
  20. H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
    [CrossRef]
  21. Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
    [CrossRef]
  22. W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
    [CrossRef]
  23. C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
    [CrossRef]
  24. T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
    [CrossRef]
  25. K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
    [CrossRef]
  26. L. J. Guo, “Recent progress in nanoimprint technology and its applications,” J. Phys. D Appl. Phys. 37(11), R123–R141 (2004).
    [CrossRef]
  27. F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
    [CrossRef] [PubMed]
  28. H. K. Cho, J. Jang, J.-H. Choi, J. Choi, J. Kim, J. S. Lee, B. Lee, Y. H. Choe, K.-D. Lee, S. H. Kim, K. Lee, S.-K. Kim, and Y.-H. Lee, “Light extraction enhancement from nano-imprinted photonic crystal GaN-based blue light-emitting diodes,” Opt. Express 14(19), 8654–8660 (2006).
    [CrossRef] [PubMed]
  29. T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
    [CrossRef]
  30. M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001).
    [CrossRef]
  31. M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
    [CrossRef]
  32. K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
    [CrossRef]
  33. S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
    [CrossRef]
  34. FullWAVE 6.1, Rsoft Design Group, Inc., http://www.rsoftdesign.com
  35. C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
    [CrossRef]
  36. K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
    [CrossRef]
  37. S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
    [CrossRef]
  38. Y. Z. Chiou, “Leakage current analysis of nitride-based photodetectors by emission microscopy inspection,” IEEE Sens. J. 8(9), 1506–1510 (2008).
    [CrossRef]

2012

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

2011

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

X.-H. Huang, J.-P. Liu, J.-J. Kong, H. Yang, and H.-B. Wang, “High-efficiency InGaN-based LEDs grown on patterned sapphire substrates,” Opt. Express 19(S4Suppl 4), A949–A955 (2011).
[CrossRef] [PubMed]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011).
[CrossRef]

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

2010

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

2009

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
[CrossRef]

2008

Y. Z. Chiou, “Leakage current analysis of nitride-based photodetectors by emission microscopy inspection,” IEEE Sens. J. 8(9), 1506–1510 (2008).
[CrossRef]

2007

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
[CrossRef]

2006

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

H. K. Cho, J. Jang, J.-H. Choi, J. Choi, J. Kim, J. S. Lee, B. Lee, Y. H. Choe, K.-D. Lee, S. H. Kim, K. Lee, S.-K. Kim, and Y.-H. Lee, “Light extraction enhancement from nano-imprinted photonic crystal GaN-based blue light-emitting diodes,” Opt. Express 14(19), 8654–8660 (2006).
[CrossRef] [PubMed]

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

2005

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

2004

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

L. J. Guo, “Recent progress in nanoimprint technology and its applications,” J. Phys. D Appl. Phys. 37(11), R123–R141 (2004).
[CrossRef]

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

2003

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

2001

M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001).
[CrossRef]

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Abe, Y.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Baek, J. H.

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Biser, J. M.

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

Borghs, G.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Brinkley, S.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

Byeon, K.-J.

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
[CrossRef]

Campos, L. M.

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

Cao, W.

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

Chan, H. M.

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

Chang, C. C.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

Chang, C. S.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Chang, S. J.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Chen, J.-J.

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

Chen, Y. J.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

Cheng, K.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Chhajed, S.

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

Chiou, Y. Z.

Y. Z. Chiou, “Leakage current analysis of nitride-based photodetectors by emission microscopy inspection,” IEEE Sens. J. 8(9), 1506–1510 (2008).
[CrossRef]

Cho, H. K.

Cho, J.

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

Cho, J.-Y.

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Cho, N.

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

Choe, Y. H.

Choi, J.

Choi, J.-H.

Choi, Y.-S.

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

Chong, K.-K.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Chuang, R. W.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Cingolani, R.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

Cojoc, D.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

David, A.

J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
[CrossRef]

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

De Vittorio, M.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

DenBaars, S.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

DenBaars, S. P.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Detchprohm, T.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Diana, F. S.

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Dierolf, V.

Ee, Y.-K.

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

Fabrizio, E. D.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

Fan, Z. Y.

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

Farrell, R. M.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Feezell, D. F.

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Feng, Z. H.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

Fujii, H.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Fujito, K.

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Gilchrist, J. F.

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

Guo, L. J.

L. J. Guo, “Recent progress in nanoimprint technology and its applications,” J. Phys. D Appl. Phys. 37(11), R123–R141 (2004).
[CrossRef]

Haeger, D. A.

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Hawker, C. J.

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

Hong, E.-J.

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Horng, R. H.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Hou, W.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Houng, M.-P.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Hsieh, M. H.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Hsu, P. S.

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Hsu, S. C.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

Hsu, T. C.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Hu, E. L.

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

Huang, S. C.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Huang, S. Y.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Huang, X.-H.

Hung, C.-I.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Hwang, J. M.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Hwang, S. Y.

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

Hwang, S.-Y.

K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
[CrossRef]

Imada, Y.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Jang, J.

Jeong, J.-H.

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

Jhin, J.

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Jiang, H. X.

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

Jou, M. J.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Jung, G. Y.

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

Jung, H. Y.

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

Jyouichi, T.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Kannaka, M.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Kao, C.-C.

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

Kato, M.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Ke, J. C.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Kelchner, K. M.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

Khizar, M.

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

Kim, D.

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

Kim, J.

Kim, J. K.

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

Kim, K. H.

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

Kim, S. H.

Kim, S.-K.

Kong, J.-J.

Ku, H.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Kudo, H.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Kumnorkaew, P.

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

Kuo, H. C.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Lai, Y.-L.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Lan, C.-C.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Lau, K. M.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

Lee, B.

Lee, B. J.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Lee, H.

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
[CrossRef]

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

Lee, J. S.

Lee, K.

Lee, K.-D.

Lee, S.-H.

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Lee, W.

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

Lee, Y. J.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Lee, Y.-H.

Leys, M.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Li, B.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Li, X. F.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

Li, X.-H.

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

Li, Y.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Li, Y.-L.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Liang, H.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Lieten, R.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Lin, C. F.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Lin, C.-L.

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

Lin, H. Y.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Lin, J. Y.

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

Lin, S. H.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Lin, Y. C.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Liu, C. Y.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

Liu, C.-C.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Liu, C.-P.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Liu, G.

H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

Liu, J.-P.

Lo, H. M.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Lu, C.-H.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Lu, T. C.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Lu, Z. D.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

Matioli, E.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

Matsumoto, H.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Megens, M. M.

J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
[CrossRef]

Meinel, I.

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Murakami, K.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Nakamura, S.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Ohuchi, Y.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Okada, N.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Okagawa, H.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Park, H.

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

Petroff, P. M.

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Poplawsky, J. D.

Qi, Y. D.

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

Rangel, E.

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

Schubert, E. F.

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

Sharma, R.

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Shei, S. C.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Shinagawa, T.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Song, R.

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

Speck, J.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

Speck, J. S.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

Stomeo, T.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

Su, Y. K.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

Su, Y.-K.

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

Sung, Y.

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

Tadatomo, K.

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Taguchi, T.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Tamura, N.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Tanaka, S.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Taniguchi, Y.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Tansu, N.

H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011).
[CrossRef]

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

Todaro, M. T.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

Truong, T. A.

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

Tsunekawa, T.

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Vinci, R. P.

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

Wang, C.-C.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Wang, H.-B.

Wang, S. C.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

Wang, W. K.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Wang, Y.-H.

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Weisbuch, C.

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Wen, K. S.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Wetzel, C.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Whitesides, G. M.

M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001).
[CrossRef]

Wierer, J. J.

J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
[CrossRef]

Wu, F.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

Wu, M.-H.

M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001).
[CrossRef]

Wuu, D. S.

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Yang, H.

Yang, K.-Y.

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

Yeom, G.

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

You, S.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Young, E. C.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

Zhang, J.

H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011).
[CrossRef]

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

Zhang, L.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

Zhao, H.

H. Zhao, G. Liu, J. Zhang, J. D. Poplawsky, V. Dierolf, and N. Tansu, “Approaches for high internal quantum efficiency green InGaN light-emitting diodes with large overlap quantum wells,” Opt. Express 19(S4Suppl 4), A991–A1007 (2011).
[CrossRef] [PubMed]

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

Zhao, L.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Zhu, M.

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

Adv. Funct. Mater.

C.-H. Lu, C.-C. Lan, Y.-L. Lai, Y.-L. Li, and C.-P. Liu, “Enhancement of green emission from InGaN/GaN multiple quantum wells via coupling to surface plasmons in a two-dimensional silver array,” Adv. Funct. Mater. 21(24), 4719–4723 (2011).
[CrossRef]

Appl. Phys. Lett.

H. Zhao, J. Zhang, G. Liu, and N. Tansu, “Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes,” Appl. Phys. Lett. 98(15), 151115 (2011).
[CrossRef]

D. S. Wuu, W. K. Wang, K. S. Wen, S. C. Huang, S. H. Lin, S. Y. Huang, C. F. Lin, and R. H. Horng, “Defect reduction and efficiency improvement of near-ultraviolet emitters via laterally overgrown GaN on a GaN/patterned sapphire template,” Appl. Phys. Lett. 89(16), 161105 (2006).
[CrossRef]

Y. Li, S. You, M. Zhu, L. Zhao, W. Hou, T. Detchprohm, Y. Taniguchi, N. Tamura, S. Tanaka, and C. Wetzel, “Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire,” Appl. Phys. Lett. 98(15), 151102 (2011).
[CrossRef]

E. Rangel, E. Matioli, Y.-S. Choi, C. Weisbuch, J. S. Speck, and E. L. Hu, “Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes,” Appl. Phys. Lett. 98(8), 081104 (2011).
[CrossRef]

E. Matioli, S. Brinkley, K. M. Kelchner, S. Nakamura, S. DenBaars, J. Speck, and C. Weisbuch, “Polarized light extraction in m-plane GaN light-emitting diodes by embedded photonic-crystals,” Appl. Phys. Lett. 98(25), 251112 (2011).
[CrossRef]

M. Khizar, Z. Y. Fan, K. H. Kim, J. Y. Lin, and H. X. Jiang, “Nitride deep-ultraviolet light-emitting diodes with microlens array,” Appl. Phys. Lett. 86(17), 173504 (2005).
[CrossRef]

S. Chhajed, W. Lee, J. Cho, E. F. Schubert, and J. K. Kim, “Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN,” Appl. Phys. Lett. 98(7), 071102 (2011).
[CrossRef]

R. M. Farrell, D. A. Haeger, P. S. Hsu, K. Fujito, D. F. Feezell, S. P. DenBaars, J. S. Speck, and S. Nakamura, “Determination of internal parameters for AlGaN-cladding-free m-plane InGaN/GaN laser diodes,” Appl. Phys. Lett. 99(17), 171115 (2011).
[CrossRef]

C.-C. Kao, Y.-K. Su, C.-L. Lin, and J.-J. Chen, “The aspect ratio effects on the performances of GaN-based light-emitting diodes with nanopatterned sapphire substrates,” Appl. Phys. Lett. 97(2), 023111 (2010).
[CrossRef]

K.-J. Byeon, S.-Y. Hwang, and H. Lee, “Fabrication of two-dimensional photonic crystal patterns on GaN-based light-emitting diodes using thermally curable monomer-based nanoimprint lithography,” Appl. Phys. Lett. 91(9), 091106 (2007).
[CrossRef]

T. A. Truong, L. M. Campos, E. Matioli, I. Meinel, C. J. Hawker, C. Weisbuch, and P. M. Petroff, “Light extraction from GaN-based light emitting diode structures with a noninvasive two-dimensional photonic crystal,” Appl. Phys. Lett. 94(2), 023101 (2009).
[CrossRef]

M.-H. Wu and G. M. Whitesides, “Fabrication of arrays of two-dimensional micropatterns using microspheres as lenses for projection photolithography,” Appl. Phys. Lett. 78(16), 2273–2275 (2001).
[CrossRef]

C.-C. Wang, H. Ku, C.-C. Liu, K.-K. Chong, C.-I. Hung, Y.-H. Wang, and M.-P. Houng, “Enhancement of the light output performance for GaN-based light-emitting diodes by bottom pillar structure,” Appl. Phys. Lett. 91(12), 121109 (2007).
[CrossRef]

Electrochem. Solid-State Lett.

H. Y. Lin, Y. J. Chen, C. C. Chang, X. F. Li, S. C. Hsu, and C. Y. Liu, “Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate,” Electrochem. Solid-State Lett. 15(3), H72–H74 (2012).
[CrossRef]

IEEE J. Quantum Electron.

S. J. Chang, C. S. Chang, Y. K. Su, R. W. Chuang, Y. C. Lin, S. C. Shei, H. M. Lo, H. Y. Lin, and J. C. Ke, “Highly reliable nitride-based LEDs with SPS+ITO upper contacts,” IEEE J. Quantum Electron. 39(11), 1439–1443 (2003).
[CrossRef]

IEEE Photon. Technol. Lett.

Y. J. Lee, J. M. Hwang, T. C. Hsu, M. H. Hsieh, M. J. Jou, B. J. Lee, T. C. Lu, H. C. Kuo, and S. C. Wang, “Enhancing the output power of GaN-based LEDs grown on wet-etched patterned sapphire substrates,” IEEE Photon. Technol. Lett. 18(10), 1152–1154 (2006).
[CrossRef]

IEEE Photonics J.

X.-H. Li, R. Song, Y.-K. Ee, P. Kumnorkaew, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency and radiation patterns of III-nitride light-emitting diodes with colloidal microlens arrays with various aspect ratios,” IEEE Photonics J. 3(3), 489–499 (2011).
[CrossRef]

IEEE Sens. J.

Y. Z. Chiou, “Leakage current analysis of nitride-based photodetectors by emission microscopy inspection,” IEEE Sens. J. 8(9), 1506–1510 (2008).
[CrossRef]

J. Appl. Phys.

J. Zhang and N. Tansu, “Improvement in spontaneous emission rates for InGaN quantum wells on ternary InGaN substrate for light-emitting diodes,” J. Appl. Phys. 110(11), 113110 (2011).
[CrossRef]

W. Cao, J. M. Biser, Y.-K. Ee, X.-H. Li, N. Tansu, H. M. Chan, and R. P. Vinci, “Dislocation structure of GaN films grown on planar and nanopatterned sapphire,” J. Appl. Phys. 110(5), 053505 (2011).
[CrossRef]

J. Cryst. Growth

Z. H. Feng, Y. D. Qi, Z. D. Lu, and K. M. Lau, “GaN-based blue light-emitting diodes grown and fabricated on patterned sapphire substrates by metalorganic vapor-phase epitaxy,” J. Cryst. Growth 272(1-4), 327–332 (2004).
[CrossRef]

J. Phys. D Appl. Phys.

L. J. Guo, “Recent progress in nanoimprint technology and its applications,” J. Phys. D Appl. Phys. 37(11), R123–R141 (2004).
[CrossRef]

Jpn. J. Appl. Phys.

L. Zhang, K. Cheng, H. Liang, R. Lieten, M. Leys, and G. Borghs, “Photoluminescence studies of polarization effects in InGaN/(In)GaN multiple quantum well structures,” Jpn. J. Appl. Phys. 51, 030207 (2012).
[CrossRef]

D. Kim, H. Lee, N. Cho, Y. Sung, and G. Yeom, “Effect of GaN microlens array on efficiency of GaN-based blue-light-emitting diodes,” Jpn. J. Appl. Phys. 44(1), L18–L20 (2005).
[CrossRef]

Microelectron. Eng.

M. De Vittorio, M. T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, and E. D. Fabrizio, “Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist,” Microelectron. Eng. 73–74, 388–391 (2004).
[CrossRef]

Nano Lett.

F. S. Diana, A. David, I. Meinel, R. Sharma, C. Weisbuch, S. Nakamura, and P. M. Petroff, “Photonic crystal-assisted light extraction from a colloidal quantum dot/GaN hybrid structure,” Nano Lett. 6(6), 1116–1120 (2006).
[CrossRef] [PubMed]

Nat. Photonics

J. J. Wierer, A. David, and M. M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009).
[CrossRef]

Opt. Express

Phys. Status Solidi A

K.-J. Byeon, H. Park, J.-Y. Cho, K.-Y. Yang, J. H. Baek, G. Y. Jung, and H. Lee, “Fabrication of photonic crystal structure on indium tin oxide electrode of GaN-based light-emitting diodes,” Phys. Status Solidi A 208(2), 480–483 (2011).
[CrossRef]

K. Tadatomo, H. Okagawa, Y. Ohuchi, T. Tsunekawa, T. Jyouichi, Y. Imada, M. Kato, H. Kudo, and T. Taguchi, “High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy,” Phys. Status Solidi A 188(1), 121–125 (2001).
[CrossRef]

Phys. Status Solidi C

T. Shinagawa, Y. Abe, H. Matsumoto, B. Li, K. Murakami, N. Okada, K. Tadatomo, M. Kannaka, and H. Fujii, “Light-emitting diodes fabricated on nanopatterned sapphire substrates by thermal lithography,” Phys. Status Solidi C 7(7-8), 2165–2167 (2010).
[CrossRef]

Semicond. Sci. Technol.

R. M. Farrell, E. C. Young, F. Wu, S. P. DenBaars, and J. S. Speck, “Materials and growth issues for high-performance nonpolar and semipolar light-emitting devices,” Semicond. Sci. Technol. 27(2), 024001 (2012).
[CrossRef]

Thin Solid Films

K.-J. Byeon, E.-J. Hong, H. Park, J.-Y. Cho, S.-H. Lee, J. Jhin, J. H. Baek, and H. Lee, “Full wafer scale nanoimprint lithography for GaN-based light-emitting diodes,” Thin Solid Films 519(7), 2241–2246 (2011).
[CrossRef]

S. Y. Hwang, H. Y. Jung, J.-H. Jeong, and H. Lee, “Fabrication of nano-sized metal patterns on flexible polyethylene-terephthalate substrate using bi-layer nanoimprint lithography,” Thin Solid Films 517(14), 4104–4107 (2009).
[CrossRef]

Other

FullWAVE 6.1, Rsoft Design Group, Inc., http://www.rsoftdesign.com

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (7)

Fig. 1
Fig. 1

The fabrication process of the patterned LED device with SiNx-based PhCs on the ITO electrode of the GaN-based LED by using NIL and reactive ion etching processes.

Fig. 2
Fig. 2

(a)–(c) are cross sectional, tilted and top views of SEM micrographs of 300 nm-high SiNx PhC patterns on the ITO electrode, respectively. (d)–(f) are also cross sectional, tilted and top views of SEM micrographs of 500 nm-high SiNx PhC patterns on the ITO electrode, respectively.

Fig. 3
Fig. 3

(a) Top and (b) cross sectional SEM images of the LED device with the SiNx PhC pattern.

Fig. 4
Fig. 4

Simplified FDTD simulation designs of (a) the conventional LED, (b) the LED with the PSS and (c) the LED with SiNx-PhC patterns and the PSS.

Fig. 5
Fig. 5

FDTD simulation results on light extraction of the conventional LED, the LED on the PSS and the SiNx-PhC patterned LED.

Fig. 6
Fig. 6

The I-V characteristics of the un-patterned LED device and LED devices with SiNx-PhC patterns of 300 nm and 500 nm in height. All LED devices were fabricated on the PSS. The inset shows the I-V characteristics on a logarithmic scale.

Fig. 7
Fig. 7

(a) EL intensity at 20 mA current and (b) EL intensity versus injection current at a wavelength of 445 nm for the un-patterned LED device and the patterned LED devices with SiNx-based PhCs.

Metrics