Effect of Mg-Preflow for p-AlGaN Electron Blocking Layer on the Electroluminescence of Green LEDs with V-Shaped Pits  

作　　者：Ai-Xing Li Chun-Lan Mo Jian-Li Zhang Xiao-Lan Wang Xiao-Ming Wn Guang-Xu Wang Jun-Lin Liu Feng-Yi Jiang 李爱星;莫春兰;张建立;王小兰;吴小明;王光绪;刘军林;江风益(National Institute of LED on Silicon Substrate,Nanchang University)

机构地区：[1]National Institute of LED on Silicon Substrate,Nanchang University

出　　处：《Chinese Physics Letters》2018年第2期88-92,共5页中国物理快报（英文版）

基　　金：Supported by the National Key R&D Program of China under Grant Nos 2016YFB0400600 and 2016YFB0400601;the State Key Program of the National Natural Science of China under Grant No 61334001;the Key R&D Program of Jiangxi Province under Grant No 20165ABC28007;the Natural Science Foundation of Jiangxi Province under Grant No 20151BAB207053;the National Natural Science Foundation of China under Grant No 21405076

摘　　要：In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in the EBL after Mg-preflow treatment,effectively alleviating the commonly observed efficiency collapse and electrons overflowing at cryogenic temperatures.However,unexpected decline in quantum efficiency is observed after Mg-preflow treatment at room temperature.Our conclusions are drawn such that the efficiency decline is probably the result of different emission positions.Higher Mg doping concentration in the EBL after Mg-preflow treatment will make it easier for a hole to be injected into multiple quantum wells with emission closer to pGaN side through the（8-plane rather than the V-shape pits,which is not favorable to luminous efficiency due to the preferred occurrence of accumulated strain relaxation and structural defects in upper QWs closer to p-GaN.Within this framework,apparently disparate experimental observations regarding electroluminescence properties,in this work,are well reconciled.In GaN-based green light-emitting diodes（LEDs） with and without Mg-preflow before the growth of p-Al GaN electron blocking layer（EBL） are investigated experimentally.A higher Mg doping concentration is achieved in the EBL after Mg-preflow treatment,effectively alleviating the commonly observed efficiency collapse and electrons overflowing at cryogenic temperatures.However,unexpected decline in quantum efficiency is observed after Mg-preflow treatment at room temperature.Our conclusions are drawn such that the efficiency decline is probably the result of different emission positions.Higher Mg doping concentration in the EBL after Mg-preflow treatment will make it easier for a hole to be injected into multiple quantum wells with emission closer to pGaN side through the（8-plane rather than the V-shape pits,which is not favorable to luminous efficiency due to the preferred occurrence of accumulated strain relaxation and structural defects in upper QWs closer to p-GaN.Within this framework,apparently disparate experimental observations regarding electroluminescence properties,in this work,are well reconciled.

关 键 词：GaN EBL Effect of Mg-Preflow for p-AlGaN Electron Blocking Layer on the Electroluminescence of Green LEDs with V-Shaped Pits 

分 类 号：TN312.8[电子电信—物理电子学]