[1] C-C Liu, Y-H Chen, M-P Houng, et al.. Improved light-output power of GaN LEDs by selective region activation [J]. IEEE Photon Technol Lett, 2004, 16(6): 1444-1446.
[2] T Nishida, H Saito, N Kobayashi. Efficient and high-power AlGaN-based ultraviolet light-emitting diode grown on bulk GaN [J]. Appl Phys Lett, 2001, 79(6): 711-712.
[3] T Fujii, Y Gao, R Sharma, et al.. Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening [J]. Appl Phys Lett, 2004, 84(6): 855-857.
[4] H S Venugopalan, X Gao, T Zhang, et al.. Fabrication of high-lumen InGaN flap chip LEDs [C]. SPIE, 2004, 5187: 260-266.
[5] S Schad, M Scherer, M Seyboth, et al.. Extraction efficiency of GaN-based LEDs [J]. Phys Stat Sol (A), 2001, 188(1): 127-130.
[6] Y J Lee, T C Lu, H C Kuo, et al.. High brightness AlGalnP-based light emitting diodes by adopting the stripe-patterned omni-directional reflector [J]. Semicond Sci Technol, 2006, 21(2): 184-189.
[7] Hongwei Liu, Qiang Kan, Chunxia Wang, et al.. Light extraction of GaN LEDs with 2-D photonic crystal structure [J]. Chin Opt Lett, 2009, 7(10): 918-920.
[8] L Chen, A Nurmikko. Fabrication and performance of efficient blue light emitting III-nitride photonic crystals [J]. Appl Phys Lett, 2004, 85(17): 3663-3665.
[9] D H Kim, C O Cho, Y G Roh, et al.. Enhanced light extraction from GaN-based light-emitting diodes with holographically generated two-dimensional photonic crystal patterns [J]. Appl Phys Lett, 2005, 87(20): 203508.
[10] C H Chao, S L Chuang, T-L Wu. Theoretical demonstration of enhancement of light extraction of flip-chip GaN light-emitting diodes with photonic crystals [J]. Appl Phys Lett, 2006, 89(9): 091116.
[11] Z Xu, L Cao, Q Tan. Enhancement of the light output of light-emitting diode with double photonic crystals [J]. Opt Commun, 2007, 278(1): 211-214.
[12] A J Danner, B Wang, S-J Chua, et al.. Fabrication of efficient light-emitting diodes with a self-assembled photonic crystal array of polystyrene nanoparticles [J]. IEEE Photon Technol Lett, 2008, 20(1-4): 48-50.
[13] E Matioli. Impact of photonic crystals on LED light extraction efficiency: approaches and limits to vertical structure designs [J]. J Phys D: Appl Phys, 2010, 43(35): 354005.
[14] C H Lin, C F Lai, T S Ko, et al.. Enhancement of InGaN-GaN indium-tin-oxide flip-chip light-emitting diodes with TiO2-SiO2 multilayer stack omnidirectional reflector [J]. IEEE Photon Technol Lett, 2006, 18(19): 2050-2052.
[15] C H Lin. Enhanced vertical extraction efficiency from a thin film InGaN-GaN light emitting diode using a 2D photonic crystal and an omni-directional reflector [J]. IEEE Photon Technol Lett, 2008, 20(10): 836-839.
[16] Xu Qingtao, Li Kang, Kong Fanmin, et al.. Enhancing extraction efficiency from GaN-based LED by using an omni-directional reflector and photonic crystal [J]. Optoelectronics Lett, 2009, 5(6): 405-408.
[17] Kyeong-Jae Byeon, Joong-Yeon Cho. Fabrication of SiNx-based photonic crystals on GaN-based LED devices with patterned sapphire substrate by nanoimprint lithography [J]. Opt Express, 2012, 20(10): 11423-11432.
[18] Zhou Shizhong, Lin Zhiting, Wang Haiyan. Research progress of patterned sapphire substrate for GaN-based light-emitting diodes [J]. Semiconductor Technology, 2012, 37(6): 417-424.
[19] Lee K S, Kwack H S, Hwang J S, et al.. Spatial correlation between optical properties and defect formation in GaN thin films laterally overgrown on cone-shaped patterned sapphire substrates [J]. J Appl Phys, 2010, 107(10): 103506.
[20] K Tadatomo, H Okagawa, Y Ohuchi. High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy [J]. Jpn J Appl Phys: Part 2-Letters, 2001, 40(6B): 583-585.
[21] Ee Y K, Li X H, Biser J. Abbreviated MOVPE nucleation of III-nitride light-emitting diodes on nano-patterned sapphire[J]. J Cryst Growth, 2010, 312(8): 1311-1315.
[22] Su Y K, Chen J J, Lin C L, et al.. Structural analysis of nitride-based LEDs grown on micro-and nanoscale patterned sapphire substrates[J]. Phys Stat Sol (C), 2010, 7(7/8): 1784-1786.
[23] H Y Lin, Y J Chen, C C Chang, et al.. Pattern-coverage effect on light extraction efficiency of GaN LED on patterned-sapphire substrate [J]. Electrochem Solid-State Lett, 2012, 15(3): H72-H74.
[24] Y Li, S You, M Zhu, et al.. Defect-reduced green GaInN/GaN light-emitting diode on nanopatterned sapphire [J]. Appl Phys Lett, 2011, 98(15): 151102.
[25] W Cao, J M Biser, Y-K Ee, et al.. Dislocation structure of GaN films grown on planar and nanopatterned sapphire [J]. J Appl Phys, 2011, 110(5): 053505.
[26] Y D Wang, K Y Zang, S J Chua, et al.. Improvement of microstructural and optical properties of GaN layer on sapphire by nano scale lateral epitaxial overgrowth [J]. Appl Phys Lett, 2006, 88(21): 211908.
[27] M T Wang, K Y Liao, Y L Li. Growth mechanism and strain variation of GaN material grown on patterned sapphire substrates with various pattern design [J]. IEEE Photon Technol Lett, 2011, 23(14): 962-964.
[28] Gao Hui, Kong Fan-Min, Li Kang, et al.. Structural optimization of GaN blue light LED with double layers of photonic crystals [J]. Acta Physica Sinica, 2012, 61(12): 127807.
[29] Hui Gao, Kang Li. Improving light extraction efficiency of GaN-based LEDs by AlxGa1-xN confining layer and embedded photonic crystals [J]. IEEE J Sel Top Quantum Electron, 2012, 18(6): 1650-1660.