Abstract

A remarkable enhancement of light extraction efficiency in GaN-based blue light-emitting diodes (LEDs) with rough beveled ZnO nanocone arrays grown on the planar indium tin oxide (ITO) layer is reported. The light output power of LEDs with rough beveled ZnO nanocone arrays was increased by about 110% at 20 mA compared with conventional LEDs with planar ITO. The light extraction efficiency of GaN-based LEDs with rough-beveled ZnO nanocones is measured much greater than with smooth-surface hexagonal ZnO nanorods. The light-ray tracing analysis showed that ZnO nanocones with rough surfaces enlarge the light escape cone of GaN-based LEDs and have a greater advantage for extracting light compared with ZnO nanorods.

© 2012 OSA

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  1. N. Holonyak, “Is the light emitting diode (LED) an ultimate lamp?” Am. J. Phys. 68(9), 864–866 (2000).
    [CrossRef]
  2. E. F. Schubert and J. K. Kim, “Solid-state light sources getting smart,” Science 308(5726), 1274–1278 (2005).
    [CrossRef] [PubMed]
  3. E. Fred, Schubert, Light-Emitting Diodes (Cambridge University Press, 2003).
  4. M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
    [CrossRef]
  5. I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
    [CrossRef]
  6. 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]
  7. R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
    [CrossRef]
  8. S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
    [CrossRef]
  9. C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
    [CrossRef]
  10. Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
    [CrossRef]
  11. J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
    [CrossRef]
  12. J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
    [CrossRef]
  13. J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
    [CrossRef]
  14. S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
    [CrossRef]
  15. Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
    [CrossRef]
  16. S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
    [CrossRef]
  17. J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
    [CrossRef]
  18. K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
    [CrossRef]
  19. M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
    [CrossRef]
  20. S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
    [CrossRef]
  21. J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
    [CrossRef]
  22. P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
    [CrossRef]
  23. C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
    [CrossRef]
  24. C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
    [CrossRef]
  25. C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
    [CrossRef]
  26. H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
    [CrossRef] [PubMed]
  27. M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
    [CrossRef]
  28. K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
    [CrossRef]
  29. H. Masui, S. Nakamura, and S. P. DenBaars, “Analytical light-ray tracing in two-dimensional objects for light-extraction problems in light-emitting diodes,” Appl. Opt. 47(1), 88–92 (2008).
    [CrossRef] [PubMed]
  30. K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
    [CrossRef]
  31. K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
    [CrossRef]
  32. B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
    [CrossRef]

2011 (1)

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

2010 (7)

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

2009 (4)

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (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]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

2008 (7)

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

H. Masui, S. Nakamura, and S. P. DenBaars, “Analytical light-ray tracing in two-dimensional objects for light-extraction problems in light-emitting diodes,” Appl. Opt. 47(1), 88–92 (2008).
[CrossRef] [PubMed]

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
[CrossRef]

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

2007 (3)

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
[CrossRef]

2006 (2)

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

2005 (2)

E. F. Schubert and J. K. Kim, “Solid-state light sources getting smart,” Science 308(5726), 1274–1278 (2005).
[CrossRef] [PubMed]

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

2004 (2)

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

2001 (1)

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

2000 (1)

N. Holonyak, “Is the light emitting diode (LED) an ultimate lamp?” Am. J. Phys. 68(9), 864–866 (2000).
[CrossRef]

1993 (1)

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

An, S. J.

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

Ang, N. S. S.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Boyle, D. S.

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

Byeon, K.-J.

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Caneau, C.

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

Chae, J. H.

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

Chang, S. J.

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Chang, S.-Y.

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

Changjean, C. H.

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Chao, C. H.

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Chao, C. L.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Chao, C.-H.

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

Chao, Y.-C.

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Chen, C. H.

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Chen, C. M.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Chen, C.-C.

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

Chen, C.-Y.

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Chen, H.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Chen, P.-C.

M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
[CrossRef]

Chen, S. Y.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Chen, W. S.

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Cheng, B. S.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Chi, G. C.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Chiu, C. H.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Cho, C.-Y.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Cho, J.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Cho, J.-Y.

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Choi, C. K.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Choi, Y.-S.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Christenson, G.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Chua, S. J.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Dai, Y.-A.

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Dalui, S.

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[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]

DenBaars, S. P.

H. Masui, S. Nakamura, and S. P. DenBaars, “Analytical light-ray tracing in two-dimensional objects for light-extraction problems in light-emitting diodes,” Appl. Opt. 47(1), 88–92 (2008).
[CrossRef] [PubMed]

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Fujii, T.

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Fujito, K.

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Gao, Y.

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Gardner, N. F.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Gessmann, T.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Gmitter, T. J.

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

Götz, W.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Govender, K.

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

He, J.-H.

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Ho, C.-L.

M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
[CrossRef]

Holonyak, N.

N. Holonyak, “Is the light emitting diode (LED) an ultimate lamp?” Am. J. Phys. 68(9), 864–866 (2000).
[CrossRef]

Hong, C.-H.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Horng, R. H.

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Hsiao, C. S.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Hu, E. L.

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Huang, H. W.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Huang, S. H.

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Hung, I. H.

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

Jeong, H.

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

Jeong, M. S.

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

Jung, G. Y.

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

Jung, G.-Y.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Kang, B. S.

B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
[CrossRef]

Kang, J. H.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Kang, J.-W.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Kenway, P. B.

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

Kern, R. S.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Kim, H.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Kim, H. G.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Kim, J. K.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

E. F. Schubert and J. K. Kim, “Solid-state light sources getting smart,” Science 308(5726), 1274–1278 (2005).
[CrossRef] [PubMed]

Kim, J. W.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Kim, J.-Y.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Kim, K. S.

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Kim, K.-K.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Kim, S.-M.

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

Kim, S.-W.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Kim, Y. C.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Ko, T. K.

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Krames, M. R.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Kuo, C. H.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Kuo, C. T.

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Kuo, C. W.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Kuo, H. C.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Kuo, W. L.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Kwon, M.-K.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Lai, W. C.

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

Le, H. Q.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Lee, C. E.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Lee, C.-T.

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

Lee, H.

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Lee, H.-Y.

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

Lee, M. L.

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

Lee, M.-K.

M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
[CrossRef]

Lee, S.-

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Lee, S.-N.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Lin, C. F.

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Lin, C.-A.

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Lin, C.-C.

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

Lin, C.-F.

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

Lin, M.-S.

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

Lin, W. H.

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Lowery, C.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Lu, T. C.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Lu, Y.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Ludowise, M. J.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Luo, H.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Mackie, D. M.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Martin, P. S.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Masui, H.

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]

Nakamura, S.

H. Masui, S. Nakamura, and S. P. DenBaars, “Analytical light-ray tracing in two-dimensional objects for light-extraction problems in light-emitting diodes,” Appl. Opt. 47(1), 88–92 (2008).
[CrossRef] [PubMed]

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

O’Brien, P.

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

O’Shea, J. J.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Oh, M.-S.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Pan, C. J.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Park, G. H.

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

Park, H.

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Park, I.-K.

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Park, J.-C.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Park, S.-J.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

Park, T.-Y.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Park, Y.

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Pearton, S. J.

B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
[CrossRef]

Pong, B. J.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Ren, F.

B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
[CrossRef]

Ryu, B. D.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Ryu, J. H.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Saraf, G.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Scherer, A.

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

Schnitzer, I.

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

Schubert, E. F.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

E. F. Schubert and J. K. Kim, “Solid-state light sources getting smart,” Science 308(5726), 1274–1278 (2005).
[CrossRef] [PubMed]

Sharma, R.

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Shei, S. C.

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Shen, C. F.

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Shen, H.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Shen, Y. C.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Sheu, J. K.

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

Soh, C. B.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Sone, C.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Song, J. J.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Steigerwald, D. A.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Stockman, S. A.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Subramanya, S.

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Tay, C. B.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Teng, J. H.

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

Tu, C. W.

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

Tun, C. J.

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

Uthirakumar, P.

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Wang, S. C.

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

Wang, W.-C.

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[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]

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

Wu, J. Y.

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Wuu, D. S.

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Xi, J. Q.

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

Yablonovitch, E.

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

Yang, C. C.

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

Yang, K.-Y.

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Yi, G. C.

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

Yi, G.-C.

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

Zhong, J.

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

Adv. Funct. Mater. (1)

K. S. Kim, S.-M. Kim, H. Jeong, M. S. Jeong, and G. Y. Jung, “Enhancement of light extraction through the wave-guiding effect of ZnO sub-microrods in InGaN blue light-emitting diodes,” Adv. Funct. Mater. 20(7), 1076–1082 (2010).
[CrossRef]

Am. J. Phys. (1)

N. Holonyak, “Is the light emitting diode (LED) an ultimate lamp?” Am. J. Phys. 68(9), 864–866 (2000).
[CrossRef]

Appl. Opt. (1)

Appl. Phys. Lett. (14)

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

B. S. Kang, S. J. Pearton, and F. Ren, “Low temperature (<100°C) patterned growth of ZnO nanorod arrays on Si,” Appl. Phys. Lett. 90(8), 083104 (2007).
[CrossRef]

M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008).
[CrossRef]

I. Schnitzer, E. Yablonovitch, C. Caneau, T. J. Gmitter, and A. Scherer, “30% external quantum efficiency from surface textured thin-film light-emitting diodes,” Appl. Phys. Lett. 63(16), 2174 (1993).
[CrossRef]

R. H. Horng, C. C. Yang, J. Y. Wu, S. H. Huang, C. E. Lee, and D. S. Wuu, “GaN-based light-emitting diodes with indium tin oxide texturing window layers using natural lithography,” Appl. Phys. Lett. 86(22), 221101 (2005).
[CrossRef]

S. J. Chang, C. F. Shen, W. S. Chen, C. T. Kuo, T. K. Ko, S. C. Shei, and J. K. Sheu, “Nitride-based light emitting diodes with indium tin oxide electrode patterned by imprint lithography,” Appl. Phys. Lett. 91(1), 013504 (2007).
[CrossRef]

C. H. Kuo, C. M. Chen, C. W. Kuo, C. J. Tun, C. J. Pan, B. J. Pong, and G. C. Chi, “Improvement of near-ultraviolet nitride-based light emitting diodes with mesh indium tin oxide contact layers,” Appl. Phys. Lett. 89(20), 201104 (2006).
[CrossRef]

J. J. Wierer, D. A. Steigerwald, M. R. Krames, J. J. O’Shea, M. J. Ludowise, G. Christenson, Y. C. Shen, C. Lowery, P. S. Martin, S. Subramanya, W. Götz, N. F. Gardner, R. S. Kern, and S. A. Stockman, “High-power AlGaInN flip-chip light-emitting diodes,” Appl. Phys. Lett. 78(22), 3379 (2001).
[CrossRef]

J. K. Sheu, I. H. Hung, W. C. Lai, S. C. Shei, and M. L. Lee, “Enhancement in output power of blue gallium nitride-based light-emitting diodes with omnidirectional metal reflector under electrode pads,” Appl. Phys. Lett. 93(10), 103507 (2008).
[CrossRef]

J. K. Kim, T. Gessmann, E. F. Schubert, J. Q. Xi, H. Luo, J. Cho, C. Sone, and Y. Park, “GaInN light-emitting diode with conductive omnidirectional reflector having a low-refractive-index indium-tin oxide layer,” Appl. Phys. Lett. 88(1), 013501 (2006).
[CrossRef]

S. J. An, J. H. Chae, G. C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

S. J. An, J. H. Chae, G.-C. Yi, and G. H. Park, “Enhanced light output of GaN-based light-emitting diodes with ZnO nanorod arrays,” Appl. Phys. Lett. 92(12), 121108 (2008).
[CrossRef]

J. Zhong, H. Chen, G. Saraf, Y. Lu, C. K. Choi, J. J. Song, D. M. Mackie, and H. Shen, “Integrated ZnO nanotips on GaN light emitting diodes for enhanced emission efficiency,” Appl. Phys. Lett. 90(20), 203515 (2007).
[CrossRef]

K.-K. Kim, S.- Lee, H. Kim, J.-C. Park, S.-N. Lee, Y. Park, S.-J. Park, and S.-W. Kim, “Enhanced light extraction efficiency of GaN-based light-emitting diodes with ZnO nanorod arrays grown using aqueous solution,” Appl. Phys. Lett. 94(7), 071118 (2009).
[CrossRef]

Electrochem. Solid-State Lett. (2)

C. H. Chiu, C. E. Lee, C. L. Chao, B. S. Cheng, H. W. Huang, H. C. Kuo, T. C. Lu, S. C. Wang, W. L. Kuo, C. S. Hsiao, and S. Y. Chen, “Enhancement of light output intensity by integrating ZnO nanorod arrays on GaN-based LLO vertical LEDs,” Electrochem. Solid-State Lett. 11(4), H84–H87 (2008).
[CrossRef]

J.-W. Kang, M.-S. Oh, Y.-S. Choi, C.-Y. Cho, T.-Y. Park, C. W. Tu, and S.-J. Park, “Improved light extraction of GaN-based green light-emitting diodes with an antireflection layer of ZnO nanorod arrays,” Electrochem. Solid-State Lett. 14(3), H120–H123 (2011).
[CrossRef]

IEEE Photon. Technol. Lett. (2)

M.-K. Lee, C.-L. Ho, and P.-C. Chen, “Light extraction efficiency enhancement of GaN blue LED by liquid-phase-deposited ZnO rods,” IEEE Photon. Technol. Lett. 20(4), 252–254 (2008).
[CrossRef]

S. Dalui, C.-C. Lin, H.-Y. Lee, C.-H. Chao, and C.-T. Lee, “Light output enhancement of GaN-based light-emitting diodes using ZnO nanorod arrays produced by aqueous solution growth technique,” IEEE Photon. Technol. Lett. 22(16), 1220–1222 (2010).
[CrossRef]

J. Cryst. Growth (1)

C. B. Soh, C. B. Tay, S. J. Chua, H. Q. Le, N. S. S. Ang, and J. H. Teng, “Optimization of hydrothermal growth ZnO Nanorods for enhancement of light extraction from GaN blue LEDs,” J. Cryst. Growth 312(11), 1848–1854 (2010).
[CrossRef]

J. Mater. Chem. (2)

K. Govender, D. S. Boyle, P. B. Kenway, and P. O’Brien, “Understanding the factors that govern the deposition and morphology of thin films of ZnO from aqueous solution,” J. Mater. Chem. 14(16), 2575–2591 (2004).
[CrossRef]

Y.-C. Chao, C.-Y. Chen, C.-A. Lin, Y.-A. Dai, and J.-H. He, “Antireflection effect of ZnO nanorod arrays,” J. Mater. Chem. 20(37), 8134–8138 (2010).
[CrossRef]

Jpn. J. Appl. Phys. (1)

Y. Gao, T. Fujii, R. Sharma, K. Fujito, S. P. Denbaars, S. Nakamura, and E. L. Hu, “Roughening hexagonal surface morphology on laser lift-off (LLO) n-face GaN with simple photo-enhanced chemical wet etching,” Jpn. J. Appl. Phys. 43(No. 5A), L637–L639 (2004).
[CrossRef]

Nanotechnology (1)

H. Park, K.-J. Byeon, K.-Y. Yang, J.-Y. Cho, and H. Lee, “The fabrication of a patterned ZnO nanorod array for high brightness LEDs,” Nanotechnology 21(35), 355304 (2010).
[CrossRef] [PubMed]

Nat. Photonics (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]

Science (1)

E. F. Schubert and J. K. Kim, “Solid-state light sources getting smart,” Science 308(5726), 1274–1278 (2005).
[CrossRef] [PubMed]

Semicond. Sci. Technol. (1)

C. H. Chao, W. H. Lin, C. H. Chen, C. H. Changjean, and C. F. Lin, “Tunable light extraction efficiency of GaN light emitting diodes by ZnO nanorod arrays,” Semicond. Sci. Technol. 24(10), 105017 (2009).
[CrossRef]

Thin Solid Films (1)

M.-S. Lin, C.-C. Chen, W.-C. Wang, C.-F. Lin, and S.-Y. Chang, “Fabrication of the selective-growth ZnO nanorods with a hole-array pattern on a p-type GaN:Mg layer through a chemical bath deposition process,” Thin Solid Films 518(24), 7398–7402 (2010).
[CrossRef]

Vacuum (1)

P. Uthirakumar, B. D. Ryu, J. H. Kang, H. G. Kim, J. H. Ryu, and C.-H. Hong, “Impact of layer thickness and light transmission of ZnO nanomaterials on GaN-based light emitting diodes,” Vacuum 85(2), 198–202 (2010).
[CrossRef]

Other (1)

E. Fred, Schubert, Light-Emitting Diodes (Cambridge University Press, 2003).

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Figures (6)

Fig. 1
Fig. 1

Schematic of GaN-based LED with ZnO nanocone arrays.

Fig. 2
Fig. 2

FE-SEM images of ZnO nanocone/nanorod arrays on the ITO layer. (a) Tilted view image of ZnO nanocone arrays. (b) Enlarged ZnO nanocones with roughened morphology. (c) Enlarged tilted view image of ZnO nanocones with cone outline. (d) Tilted view image of ZnO nanorod arrays.

Fig. 3
Fig. 3

(a) I-V characteristic curves of C-LED, NC-LED and NR-LED. (b) LOP curves of GaN-based C-LED, NC-LED and NR-LED as a function of injection current.

Fig. 4
Fig. 4

EL spectrum of C-LED, NC-LED and NR-LED at 20 mA and 100 mA.

Fig. 5
Fig. 5

(a) Schematic of photons emitted through the top surface of GaN-based LED with ZnO nanorods on ITO. (b) Schematic of photons emitted through top surface of GaN-based LED with rough beveled ZnO nanocones on ITO.

Fig. 6
Fig. 6

Ray dynamics for rectangle and isosceles triangle. (a)-(c) Light ray traces in rectangles. (d)-(f) Light ray traces in isosceles triangle.

Equations (3)

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π/2 θ c < θ 0 <π/2:Output at 1st incidence.
0< θ 0 < θ c :Output at n-th incidence.
θ c < θ 0 <π/2 θ c :Trapped in rectangle.

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