Optimization of Light Extraction Efficiency of III-Nitride LEDs With Self-Assembled Colloidal-Based Microlenses

被引：127
作者：
Ee, Yik-Khoon [1 ]
Kumnorkaew, Pisist [2 ]
Arif, Ronald A. [1 ]
Tong, Hua [1 ]
Zhao, Hongping [1 ]
Gilchrist, James F. [2 ]
Tansu, Nelson [1 ]
机构：
[1] Lehigh Univ, Ctr Opt Technol, Dept Elect & Comp Engn, Bethlehem, PA 18015 USA
[2] Lehigh Univ, Dept Chem Engn, Ctr Adv Mat & Nanotechnol, Bethlehem, PA 18015 USA
来源：
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS | 2009年 / 15卷 / 04期
基金：
美国国家科学基金会;
关键词：
Colloid; InGaN quantum wells (QWs); LEDs; light extraction efficiency; microlens arrays; QUANTUM-WELL STRUCTURES; EMITTING DIODE; SURFACE; BLUE; DEPOSITION; ARRAYS;
D O I：
10.1109/JSTQE.2009.2015580
中图分类号：
TM [电工技术]; TN [电子技术、通信技术];
学科分类号：
0808 ; 0809 ;
摘要：
Improvement of light extraction efficiency of InGaN LEDs using colloidal-based SiO2/polystyrene (PS) microlens arrays was demonstrated. The size effect of the SiO2 microspheres and the thickness effect of the PS layer on the light extraction efficiency of III-nitride LEDs were studied. The monolayer rapid convective deposition conditions for SiO2 microspheres were also investigated. Ray tracing simulations show that the use of microlens arrays can lead to increase in light extraction efficiency of InGaN LEDs by 2.64 times. This is consistent with experiments that demonstrated 2.49 times improvement in light extraction utilizing SiO2/PS microlens arrays. The enhancement in light extraction efficiency is attributed to increase in effective photon escape cone due to SiO2/PS microlens arrays, and reduced Fresnel reflection within the photon escape cone due to the grading of refractive index change between GaN/SiO2/PS/air interface.
引用
收藏
页码：1218 / 1225
页数：8
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