Abstract

Improvement of light extraction efficiency of InGaN light emitting diodes (LEDs) using polydimethylsiloxane (PDMS) concave microstructures arrays was demonstrated. The size effect of the concave microstructures on the light extraction efficiency of III-Nitride LEDs was studied. Depending on the size of the concave microstructures, ray tracing simulations show that the use of PDMS concave microstructures arrays can lead to increase in light extraction efficiency of InGaN LEDs by 1.5 to 2.0 times. Experiments utilizing 2.0 micro n thick PDMS with 1.0 micron diameter of the PDMS concave microstructures arrays demonstrated 1.70 times improvement in light extraction efficiency, which is consistent with improvement of 1.77 times predicted from simulation. The enhancement in light extraction efficiency is attributed to increase in effective photon escape cone due to PDMS concave microstructures arrays.

© 2009 OSA

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2009

H. Zhao, R. A. Arif, and N. Tansu, “Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500-540 nm,” IEEE J. Sel. Top. Quantum Electron. 15, 1104–1114 (2009).
[CrossRef]

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

2008

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

H. Zhao, R. A. Arif, and N. Tansu, “Self Consistent Gain Analysis of Type-II ‘W’ InGaN-GaNAs Quantum Well Lasers,” J. Appl. Phys. 104(4), 043104 (2008).
[CrossRef]

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

2007

R. A. Arif, Y. K. Ee, and N. Tansu, “Polarization Engineering via Staggered InGaN Quantum Wells for Radiative Efficiency Enhancement of Light Emitting Diodes,” Appl. Phys. Lett. 91(9), 091110 (2007).
[CrossRef]

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

2006

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

2005

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

T. Kim, A. J. Danner, and K. D. Choquette, “Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating,” Electron. Lett. 41(20), 1138–1139 (2005).
[CrossRef]

N. Tansu and L. J. Mawst, “Current Injection Efficiency of 1300-nm InGaAsN Quantum-Well Lasers,” J. Appl. Phys. 97(5), 054502 (2005).
[CrossRef]

2004

B. G. Prevo and O. D. Velev, “Controlled, rapid deposition of structured coatings from micro- and nanoparticle suspensions,” Langmuir 20(6), 2099–2107 (2004).
[CrossRef]

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

2003

R. Horvath, L. R. Lindvold, and N. B. Larsen, “Fabrication of all-polymer freestanding waveguides,” J. Micromech. Microeng. 13(3), 419–424 (2003).
[CrossRef]

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

2002

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Arif, R. A.

H. Zhao, R. A. Arif, and N. Tansu, “Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500-540 nm,” IEEE J. Sel. Top. Quantum Electron. 15, 1104–1114 (2009).
[CrossRef]

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

H. Zhao, R. A. Arif, and N. Tansu, “Self Consistent Gain Analysis of Type-II ‘W’ InGaN-GaNAs Quantum Well Lasers,” J. Appl. Phys. 104(4), 043104 (2008).
[CrossRef]

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

R. A. Arif, Y. K. Ee, and N. Tansu, “Polarization Engineering via Staggered InGaN Quantum Wells for Radiative Efficiency Enhancement of Light Emitting Diodes,” Appl. Phys. Lett. 91(9), 091110 (2007).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

Balandin, A. A.

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Chen, M.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Choi, H. W.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Choquette, K. D.

T. Kim, A. J. Danner, and K. D. Choquette, “Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating,” Electron. Lett. 41(20), 1138–1139 (2005).
[CrossRef]

Dai, J. J.

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

Danner, A. J.

T. Kim, A. J. Danner, and K. D. Choquette, “Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating,” Electron. Lett. 41(20), 1138–1139 (2005).
[CrossRef]

David, A.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Dawson, M. D.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

DenBaars, S.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

DenBaars, S. P.

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Ee, Y. K.

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

R. A. Arif, Y. K. Ee, and N. Tansu, “Polarization Engineering via Staggered InGaN Quantum Wells for Radiative Efficiency Enhancement of Light Emitting Diodes,” Appl. Phys. Lett. 91(9), 091110 (2007).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

Ferguson, I.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Florescu, D. I.

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Fujii, T.

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Gao, Y.

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Gilchrist, J. F.

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

Girkin, J. M.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Gu, E.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Gupta, S.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Horvath, R.

R. Horvath, L. R. Lindvold, and N. B. Larsen, “Fabrication of all-polymer freestanding waveguides,” J. Micromech. Microeng. 13(3), 419–424 (2003).
[CrossRef]

Hu, E. L.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Huh, C.

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

Iza, M.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Jang, J.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Jeon, S. K.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Kang, E. J.

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

Kim, C. H.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Kim, J. K.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

Kim, T.

T. Kim, A. J. Danner, and K. D. Choquette, “Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating,” Electron. Lett. 41(20), 1138–1139 (2005).
[CrossRef]

Kotchetkov, D.

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Kumnorkaew, P.

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

Larsen, N. B.

R. Horvath, L. R. Lindvold, and N. B. Larsen, “Fabrication of all-polymer freestanding waveguides,” J. Micromech. Microeng. 13(3), 419–424 (2003).
[CrossRef]

Lee, K. S.

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

Lin, C. F.

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

Lin, S. Y.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Lindvold, L. R.

R. Horvath, L. R. Lindvold, and N. B. Larsen, “Fabrication of all-polymer freestanding waveguides,” J. Micromech. Microeng. 13(3), 419–424 (2003).
[CrossRef]

Liu, C.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Liu, W.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Luo, H.

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

Matioli, E.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Mawst, L. J.

N. Tansu and L. J. Mawst, “Current Injection Efficiency of 1300-nm InGaAsN Quantum-Well Lasers,” J. Appl. Phys. 97(5), 054502 (2005).
[CrossRef]

McConnell, G.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

McGroddy, K.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Nakamura, S.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Park, E. H.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Park, J. S.

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Park, S. J.

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

Pasquale, A. J.

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

Pollak, F. H.

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Prevo, B. G.

B. G. Prevo and O. D. Velev, “Controlled, rapid deposition of structured coatings from micro- and nanoparticle suspensions,” Langmuir 20(6), 2099–2107 (2004).
[CrossRef]

Schubert, E. F.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

Schubert, M. F.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Sharma, R.

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

Smart, J. A.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Speck, J. S.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Tansu, N.

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

H. Zhao, R. A. Arif, and N. Tansu, “Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500-540 nm,” IEEE J. Sel. Top. Quantum Electron. 15, 1104–1114 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

H. Zhao, R. A. Arif, and N. Tansu, “Self Consistent Gain Analysis of Type-II ‘W’ InGaN-GaNAs Quantum Well Lasers,” J. Appl. Phys. 104(4), 043104 (2008).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

R. A. Arif, Y. K. Ee, and N. Tansu, “Polarization Engineering via Staggered InGaN Quantum Wells for Radiative Efficiency Enhancement of Light Emitting Diodes,” Appl. Phys. Lett. 91(9), 091110 (2007).
[CrossRef]

N. Tansu and L. J. Mawst, “Current Injection Efficiency of 1300-nm InGaAsN Quantum-Well Lasers,” J. Appl. Phys. 97(5), 054502 (2005).
[CrossRef]

Tong, H.

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

Velev, O. D.

B. G. Prevo and O. D. Velev, “Controlled, rapid deposition of structured coatings from micro- and nanoparticle suspensions,” Langmuir 20(6), 2099–2107 (2004).
[CrossRef]

Watson, I. M.

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Weisbuch, C.

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

Xi, J. Q.

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

Yang, Z. J.

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

Zhao, H.

H. Zhao, R. A. Arif, and N. Tansu, “Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500-540 nm,” IEEE J. Sel. Top. Quantum Electron. 15, 1104–1114 (2009).
[CrossRef]

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

H. Zhao, R. A. Arif, and N. Tansu, “Self Consistent Gain Analysis of Type-II ‘W’ InGaN-GaNAs Quantum Well Lasers,” J. Appl. Phys. 104(4), 043104 (2008).
[CrossRef]

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

Zheng, J. H.

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

Zou, J.

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

Appl. Phys. Lett.

R. A. Arif, Y. K. Ee, and N. Tansu, “Polarization Engineering via Staggered InGaN Quantum Wells for Radiative Efficiency Enhancement of Light Emitting Diodes,” Appl. Phys. Lett. 91(9), 091110 (2007).
[CrossRef]

T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855–857 (2004).
[CrossRef]

K. McGroddy, A. David, E. Matioli, M. Iza, S. Nakamura, S. DenBaars, J. S. Speck, C. Weisbuch, and E. L. Hu, “Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes,” Appl. Phys. Lett. 93(10), 103502 (2008).
[CrossRef]

H. W. Choi, C. Liu, E. Gu, G. McConnell, J. M. Girkin, I. M. Watson, and M. D. Dawson, “GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses,” Appl. Phys. Lett. 84(13), 2253–2255 (2004).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, J. F. Gilchrist, and N. Tansu, “Enhancement of light extraction efficiency of InGaN quantum wells light emitting diodes using SiO2/polystyrene microlens arrays,” Appl. Phys. Lett. 91(22), 221107 (2007).
[CrossRef]

E. H. Park, J. Jang, S. Gupta, I. Ferguson, C. H. Kim, S. K. Jeon, and J. S. Park, “Air-voids embedded high efficiency InGaN-light emitting diode,” Appl. Phys. Lett. 93(19), 191103 (2008).
[CrossRef]

Electron. Lett.

T. Kim, A. J. Danner, and K. D. Choquette, “Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating,” Electron. Lett. 41(20), 1138–1139 (2005).
[CrossRef]

IEEE J. Quantum Electron.

R. A. Arif, H. Zhao, Y. K. Ee, and N. Tansu, “Spontaneous Emission and Characteristics of Staggered InGaN Quantum Wells Light Emitting Diodes,” IEEE J. Quantum Electron. 44(6), 573–580 (2008).
[CrossRef]

H. Zhao, R. A. Arif, Y. K. Ee, and N. Tansu, “Self-Consistent Analysis of Strain-Compensated InGaN-AlGaN Quantum Wells for Lasers and Light Emitting Diodes,” IEEE J. Quantum Electron. 45(1), 66–78 (2009).
[CrossRef]

IEEE J. Sel. Top. Quantum Electron.

H. Zhao, R. A. Arif, and N. Tansu, “Design Analysis of Staggered InGaN Quantum Wells Light-Emitting Diodes at 500-540 nm,” IEEE J. Sel. Top. Quantum Electron. 15, 1104–1114 (2009).
[CrossRef]

Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, H. Zhao, J. F. Gilchrist, and N. Tansu, “Optimization of Light Extraction Efficiency of III-Nitride Light Emitting Diodes with Self-Assembled Colloidal-based Microlenses,” IEEE J. Sel. Top. Quantum Electron. 15, 1218–1225 (2009).
[CrossRef]

IEEE Photon. Technol. Lett.

C. F. Lin, Z. J. Yang, J. H. Zheng, and J. J. Dai, “Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall,” IEEE Photon. Technol. Lett. 17(10), 2038–2040 (2005).
[CrossRef]

J. Q. Xi, H. Luo, A. J. Pasquale, J. K. Kim, and E. F. Schubert, “Enhanced light extraction in GaInN light-emitting diode with pyramid reflector,” IEEE Photon. Technol. Lett. 18(22), 2347–2349 (2006).
[CrossRef]

J. Appl. Phys.

H. Zhao, R. A. Arif, and N. Tansu, “Self Consistent Gain Analysis of Type-II ‘W’ InGaN-GaNAs Quantum Well Lasers,” J. Appl. Phys. 104(4), 043104 (2008).
[CrossRef]

C. Huh, K. S. Lee, E. J. Kang, and S. J. Park, “Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface,” J. Appl. Phys. 93(11), 9383–9385 (2003).
[CrossRef]

J. Zou, D. Kotchetkov, A. A. Balandin, D. I. Florescu, and F. H. Pollak, “Thermal conductivity of GaN films: Effects of impurities and dislocations,” J. Appl. Phys. 92(5), 2534–2539 (2002).
[CrossRef]

N. Tansu and L. J. Mawst, “Current Injection Efficiency of 1300-nm InGaAsN Quantum-Well Lasers,” J. Appl. Phys. 97(5), 054502 (2005).
[CrossRef]

J. Micromech. Microeng.

R. Horvath, L. R. Lindvold, and N. B. Larsen, “Fabrication of all-polymer freestanding waveguides,” J. Micromech. Microeng. 13(3), 419–424 (2003).
[CrossRef]

Langmuir

B. G. Prevo and O. D. Velev, “Controlled, rapid deposition of structured coatings from micro- and nanoparticle suspensions,” Langmuir 20(6), 2099–2107 (2004).
[CrossRef]

P. Kumnorkaew, Y. K. Ee, N. Tansu, and J. F. Gilchrist, “Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays,” Langmuir 24(21), 12150–12157 (2008).
[CrossRef] [PubMed]

Nat. Photonics

J. Q. Xi, M. F. Schubert, J. K. Kim, E. F. Schubert, M. Chen, S. Y. Lin, W. Liu, and J. A. Smart, “Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection,” Nat. Photonics 1, 176–179 (2007).

Other

A. J. Fischer, F. W. Mont, J. K. Kim, E. F. Schubert, D. D. Koleske, and M. H. Crawford, “Enhanced Light-Extraction from InGaN Quantum Wells Using Refractive-Index-Matched TiO2”, in Proc. of the Conference on Lasers and Electro-Optics (Baltimore, MD, 2007) Paper No. CTuI2.

J. E. Mark, Handbook of Polymers, (Oxford University Press, 1999) pp. 424. .

Need Project, Intermediate Energy Infobook, (US Department of Energy, pp. 51, 2008).

E. F. Schubert, Light Emitting Diodes, (Cambridge University Press, pp. 145, 2006).

S. Nakamura, and S. Pearton, S., and G. Fasol, The Blue Laser Diode, (Springer-Verlag Berlin Heidelberg, 2000) pp. 7, .

J. K. Kim, M. F. Schubert, J. Q. Xi, F. W. Mont, and E. F. Schubert, “Enhancement of light extraction in GaInN light-emitting diodes with graded-index indium tin oxide layer”, in Proc. of the Conference on Lasers and Electro-Optics (Baltimore, MD, 2007) Paper No. CTuI1.

S. J. Lee, J. Lee, S. Kim, and H. Jeon, “Fabrication of reflective GaN mesa sidewalls for the application to high extraction efficiency LEDs,” Phys. Stat. Solidi (c) 4, 2625- 2628 (2007).
[CrossRef]

J. J. Wierer, M. R. Krames, J. E. Epler, N. F. Gardner, J. R. Wendt, M. M. Sigalas, S. R. J. Brueck, D. Li, and M. Shagam, “III-nitride LEDs with photonic crystal structures”, in Proc. SPIE, 5739, 102–107 (2005).
[CrossRef]

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Figures (11)

Fig. 1.
Fig. 1.

Schematic of InGaN QWs LEDs structure utilizing PDMS concave microstructures arrays, on the top emitting InGaN LED.

Fig. 2.
Fig. 2.

(a) Schematic of InGaN QWs LEDs simulation mesh structure utilizing PDMS concave microstructures arrays on the top emission surface, and (b) flow chart of Monte Carlo ray tracing simulation to calculate the light extraction efficiency of the LED.

Fig. 3.
Fig. 3.

Comparison of light extraction efficiency ratios of InGaN LEDs with varying concave microstructures diameter, and emission wavelength, with PDMS layer thickness of (a) 3.0µm, and (b) 2.0µm.

Fig. 4.
Fig. 4.

Schematic of rapid convective deposition of SiO2 microspheres on glass substrate.

Fig. 5.
Fig. 5.

Confocal laser scanning microscopy images of monolayer SiO2 microspheres arrays on glass substrate, used as imprinting template for forming PDMS concave microstructures arrays.

Fig. 6.
Fig. 6.

Process flow of depositing PDMS concave microstructures arrays on InGaN QWsLEDs.

Fig. 7.
Fig. 7.

Scanning electron microscopy micrograph of PDMS concave microstructures arrays on InGaN QW LEDs.

Fig. 8.
Fig. 8.

Comparison of electroluminescence intensity of InGaN QW LEDs, with and without (a) 3.0µm thick PDMS layer (LED-A), and (b) 2.0µm thick PDMS layer (LED-B) with dconcave=1.0µm concave microstructures arrays.

Fig. 9.
Fig. 9.

Comparison of electroluminescence spectra of LED-A and LED-B coated with PDMS concave microstructures arrays and uncoated sample, at the injection current density level of 80 A/cm2.

Fig. 10.
Fig. 10.

Micrograph images of LED-B (a) without coating, and (b) with 2.0µm thick PDMS dconcave=1.0µm concave microstructures arrays at current injection level of 100mA.

Fig. 11.
Fig. 11.

Electroluminescence intensity of LED-B, with and without 2.0µm thick PDMS layer with dconcave=1.0µm concave microstructures arrays, with operating temperatures from 30°C to 70°C.

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