Light Extraction Efficiency and Radiation Patterns of III-Nitride Light-Emitting Diodes With Colloidal Microlens Arrays With Various Aspect Ratios

The fabrication studies of silica/polystyrene (PS) colloidal microlens arrays with various aspect ratios were performed on the III-nitride light-emitting diodes (LEDs). The use of colloidal-based microlens arrays led to significant enhancement in light extraction efficiency for III-nitride LEDs. In varying the aspect ratios of the microlens arrays, the engineering of various PS thicknesses was employed by using high-temperature treatment and redeposition process. The effects of PS thickness on the light extraction efficiency and far-field emission patterns of InGaN quantum-well (QW) LEDs were studied. The total output powers of microlens LEDs with various PS thicknesses exhibited 1.93-2.70 times enhancement over that of planar LEDs, and the use of optimized PS layer thickness is important in leading the enhancement of the light extraction efficiency in large angular direction.

[1]  Seoung-Hwan Park,et al.  Dip-shaped InGaN/GaN quantum-well light-emitting diodes with high efficiency , 2009 .

[2]  Hao-Chung Kuo,et al.  Enhanced light output of an InGaN/GaN light emitting diode with a nano-roughened p-GaN surface , 2005 .

[3]  Ivan Moreno,et al.  Modeling the radiation pattern of LEDs. , 2008, Optics express.

[4]  A. A. Allerman,et al.  Improved brightness of 380 nm GaN light emitting diodes through intentional delay of the nucleation island coalescence , 2002 .

[5]  Umesh K. Mishra,et al.  High quantum efficiency InGaN/GaN solar cells with 2.95 eV band gap , 2008 .

[6]  Jing Zhang,et al.  Characterizations of Seebeck coefficients and thermoelectric figures of merit for AlInN alloys with various In-contents , 2011 .

[7]  Rajendra Dahal,et al.  Thermoelectric Properties of In0.3Ga0.7N Alloys , 2009 .

[8]  Yik-Khoon Ee,et al.  Light extraction efficiency enhancement of InGaN quantum wells light-emitting diodes with polydimethylsiloxane concave microstructures. , 2009, Optics express.

[9]  Mathew C. Schmidt,et al.  Demonstration of Nonpolar m-Plane InGaN/GaN Laser Diodes , 2007 .

[10]  S. Denbaars,et al.  Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening , 2004 .

[11]  Ian T. Ferguson,et al.  Design and characterization of GaN∕InGaN solar cells , 2007 .

[12]  Jing Zhang,et al.  Thermoelectric properties of lattice-matched AlInN alloy grown by metal organic chemical vapor deposition , 2010 .

[13]  Ronald A. Arif,et al.  Design and characteristics of staggered InGaN quantum-well light-emitting diodes in the green spectral regime , 2009 .

[14]  Nelson Tansu,et al.  Surface plasmon dispersion engineering via double-metallic Au/Ag layers for III-nitride based light-emitting diodes , 2011 .

[15]  Seong-Ju Park,et al.  Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface , 2003 .

[16]  Yik-Khoon Ee,et al.  Investigation of the deposition of microsphere monolayers for fabrication of microlens arrays. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[17]  M.H. Crawford,et al.  LEDs for Solid-State Lighting: Performance Challenges and Recent Advances , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[18]  Hisashi Yamada,et al.  Continuous-wave Operation of AlGaN-cladding-free Nonpolar m-Plane InGaN/GaN Laser Diodes , 2007 .

[19]  Hirofumi Kan,et al.  Radiative and nonradiative recombination in an ultraviolet GaN/AlGaN multiple-quantum-well laser diode , 2010 .

[20]  Nelson Tansu,et al.  Selective area epitaxy of ultra-high density InGaN quantum dots by diblock copolymer lithography , 2011, Nanoscale research letters.

[21]  Chia-Feng Lin,et al.  Enhanced light output in nitride-based light-emitting diodes by roughening the mesa sidewall , 2005 .

[22]  Yik-Khoon Ee,et al.  Enhancement of Light Extraction Efficiency of InGaN Quantum Wells LEDs Using SiO2 Microspheres , 2007, 2007 Conference on Lasers and Electro-Optics (CLEO).

[23]  Seoung-Hwan Park,et al.  High-efficiency staggered 530 nm InGaN/InGaN/GaN quantum-well light-emitting diodes , 2009 .

[24]  Jonathan J. Wierer,et al.  III -nitride photonic-crystal light-emitting diodes with high extraction efficiency , 2009 .

[25]  Yujie J. Ding,et al.  Efficient Terahertz Generation Within InGaN/GaN Multiple Quantum Wells , 2011, IEEE Journal of Selected Topics in Quantum Electronics.

[26]  Kent D. Choquette,et al.  Enhancement in external quantum efficiency of blue light-emitting diode by photonic crystal surface grating , 2005 .

[27]  E. Fred Schubert,et al.  Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection , 2007 .

[28]  Joonhee Lee,et al.  Fabrication of reflective GaN mesa sidewalls for the application to high extraction efficiency LEDs , 2007 .

[29]  Michael R. Krames,et al.  Blue-emitting InGaN–GaN double-heterostructure light-emitting diodes reaching maximum quantum efficiency above 200A∕cm2 , 2007 .

[30]  Michael Kneissl,et al.  Continuous-wave operation of ultraviolet InGaN/InAlGaN multiple-quantum-well laser diodes , 2003 .

[31]  J. Gilchrist,et al.  Optimization of Light Extraction Efficiency of III-Nitride LEDs With Self-Assembled Colloidal-Based Microlenses , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[32]  J. Lin,et al.  Thermoelectric Properties of In_x_Ga_1-x_N Alloys , 2008 .

[33]  C. Zah,et al.  Optical gain and gain saturation of blue‐green InGaN quantum wells , 2010 .

[34]  T. Karabacak,et al.  Low temperature melting of copper nanorod arrays , 2006 .

[35]  Nelson Tansu,et al.  Large optical gain AlGaN-delta-GaN quantum wells laser active regions in mid- and deep-ultraviolet spectral regimes , 2011 .

[36]  Yik-Khoon Ee,et al.  Metalorganic Vapor Phase Epitaxy of III-Nitride Light-Emitting Diodes on Nanopatterned AGOG Sapphire Substrate by Abbreviated Growth Mode , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[37]  Yen-Kuang Kuo,et al.  Improvement in output power of a 460 nm InGaN light-emitting diode using staggered quantum well , 2010 .

[38]  J.-Q. Xi,et al.  Enhanced Light Extraction in GaInN Light-Emitting Diode With Pyramid Reflector , 2006, IEEE Photonics Technology Letters.

[39]  E. Schubert,et al.  Polarization-matched GaInN∕AlGaInN multi-quantum-well light-emitting diodes with reduced efficiency droop , 2008 .

[40]  S. G. Bishop,et al.  GaN epitaxial lateral overgrowth and optical characterization , 1998 .

[41]  F. Mont,et al.  Enhancement of Light Extraction in GaInN Light-Emitting Diodes with Graded-Index Indium Tin Oxide Layer , 2007, 2007 Conference on Lasers and Electro-Optics (CLEO).

[42]  Taeil Jung,et al.  Novel Epitaxial Nanostructures for the Improvement of InGaN LEDs Efficiency , 2009, IEEE Journal of Selected Topics in Quantum Electronics.

[43]  James S. Speck,et al.  Directionality control through selective excitation of low-order guided modes in thin-film InGaN photonic crystal light-emitting diodes , 2011 .

[44]  J. Gilchrist,et al.  Effect of nanoparticle concentration on the convective deposition of binary suspensions. , 2009, Langmuir : the ACS journal of surfaces and colloids.

[45]  Rajendra Dahal,et al.  InGaN/GaN multiple quantum well solar cells with long operating wavelengths , 2009 .

[46]  Q-Han Park,et al.  Enhanced light extraction from GaN-based light-emitting diodes with holographically generated two-dimensional photonic crystal patterns , 2005 .

[47]  Erdan Gu,et al.  GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses , 2004 .

[48]  S. G. Bishop,et al.  The incorporation of arsenic in GaN by metalorganic chemical vapor deposition , 1998 .

[49]  E. Fred Schubert,et al.  Strong light extraction enhancement in GaInN light-emitting diodes by using self-organized nanoscale patterning of p-type GaN , 2011 .

[50]  Ronald A. Arif,et al.  Current injection efficiency induced efficiency-droop in InGaN quantum well light-emitting diodes , 2010, DRC 2010.

[51]  Andreas Breidenassel,et al.  500 nm electrically driven InGaN based laser diodes , 2009 .