GaN基LED中V形坑缺陷的研究进展  

Research Progress on V-Shaped Pit Defects of GaN-Based LED

作　　者：刘青明 尚林 邢茹萍 侯艳艳 张帅 黄佳瑶 马淑芳 许并社 LIU Qingming;SHANG Lin;XING Ruping;HOU Yanyan;ZHANG Shuai;HUANG Jiayao;MA Shufang;XU Bingshe(Institute of Atomic and Molecular Science,Frontier Institute of Science and Technology,Shaanxi University of Science and Technology,Xi'an 710021,China;Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]陕西科技大学前沿科学与技术转移研究院材料原子·分子科学研究所,陕西西安710021 [2]太原理工大学新材料界面科学与工程教育部重点实验室,山西太原030024

出　　处：《中国材料进展》2020年第12期968-973,共6页Materials China

基　　金：国家重点研发计划项目(2016YFB0401803);山西省重点研发计划项目(201703D111026)。

摘　　要：自低温AlN、GaN形核技术和高温热退火技术实现了外延高质量GaN薄膜和激活p型GaN受主以来,GaN基光电器件得到了迅猛发展。但是,GaN基光电器件依然存在诸多基础性问题,特别是基于异质衬底外延的GaN基LED外延层中的位错密度高达10^(8) cm^(-2),内量子效率却超过50%。V形坑是GaN基LED外延层中一种常见的倒金字塔缺陷,6个侧面与c面的夹角均为62°。基于V形坑缺陷对LED光电性能影响的研究成果,介绍了V形坑中侧壁量子阱屏蔽位错理论:侧壁量子阱的In含量较低,其势垒高度大于c面量子阱,故在穿透位错周围形成了高势垒,阻挡载流子被非辐射复合中心所捕获。此外,还综述了V形坑缺陷的形成机理、附近区域的发光特性、对LED电学特性的影响以及通过优化V形坑调控LED光电性能的研究。Based on the low-temperature nucleation technology of AlN and GaN,as well as high-temperature thermal annealing technology,the epitaxial growth of high-quality GaN thin films and the activation of p-GaN acceptor has been realized.Since then,GaN-based optoelectronic devices have a great development.However,there are still some fundamental problems for GaN-based optoelectronic devices.Especially,the internal quantum efficiency of GaN-based LED epitaxially grown on heterogeneous substrates is more than 50%while its dislocation density is as high as 10^(8) cm^(-2).V-shaped pits in the shape of inverted pyramid are common defects in the epitaxial layer of GaN-based LEDs.There are six side-walls in V-shaped pits,and these side-walls all have the angle of 62°with c-plane.Based on the research results of influence of V-shaped pits on optical and electrical properties of LEDs,the screening dislocation theory induced by sidewall quantum wells(QWs)in V-shaped pits was introduced.Owing to the low In content,the barrier height of sidewall QWs is much higher than that of c-plane QWs.Therefore,a high barrier formed around the threading dislocation,which prevents carriers from being captured by the non-radiative recombination center.Moreover,the formation mechanism,surrounding optical properties of V-shaped pits and its influence on electrical properties of LEDs were also reviewed.Meanwhile,the research on optical and electrical properties of LED controlled by V-shaped pits optimization was discussed.

关 键 词：氮化镓 V形坑缺陷 非辐射复合 光电性能 

分 类 号：TN311.5[电子电信—物理电子学]