Tuning a nano-pillar array for enhancing the photoluminescence extraction efficiency of GaN-based light-emitting diodes

作     者：陈夏 梁柱洪 陈湛旭 杨伟明 陈土福 金崇君 张佰君 

作者机构：State Key Laboratory of Optoelectronic Materials and Technologies School of Physics and Engineering Sun Yat-Sen University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2013年第22卷第4期

页      面：519-522页

核心收录：

学科分类：08[工学] 09[农学] 0903[农学-农业资源与环境] 0803[工学-光学工程] 

基　　金：Project supported by the the National Natural Science Foundation of China (Grant Nos. 10774195, U0834001, 10974263, 11174374, and 10725420) the KeyProgram of Ministry of Education, China (Grant No. 309024) the New Century Excellent Talents in University, and the National Basic Research Program of China (Grant No. 2010CB923200) 

主　　题：colloidal lithography light-emitting diode extraction efficiency 

摘      要：We demonstrate the fabrication of hexagonal nano-pillar arrays at the surface of GaN-based light-emitting diodes （LEDs） by nanosphere lithography. By varying the oxygen plasma etching time, we could tune the size and shape of the pillar. The nano-pillar has a truncated cone shape. The nano-pillar array serves as a gradual effective refractive index matcher, which reduces the reflection and increases light cone. It is found that the patterned surface absorbs more pumping light. To compare extraction efficiencies of LEDs, it is necessary to normalize the photoluminescence power spectrum with total absorption rate under fixed pumping power, then we could obtain the correct enhancement factor of the photoluminescence extraction efficiency and optimized structure. The highest enhancement factor of the extraction efficiency is 10.6.