文章信息/Info

Title:

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

文章編號:

1674-3962(2020)12-0968-06

作者:

劉青明1; 尚林1; 邢茹萍1; 侯艷艷1; 張帥1; 黃佳瑤1; 馬淑芳1; 許并社1; 2

（1. 陜西科技大學前沿科學與技術轉移研究院 材料原子·分子科學研究所，陜西 西安 710021）（2. 太原理工大學 新材料界面科學與工程教育部重點實驗室，山西 太原 030024）

Author(s):

LIU Qingming1;  SHANG Lin1;  XING Ruping1;  HOU Yanyan1;  ZHANG Shuai1;  HUANG Jiayao1; MA Shufang1; XU Bingshe1; 2

(1. Institute of Atomic and Molecular Science, Frontier Institute of Science and Technology, Shaanxi University of Science and Technology, Xi’an 710021, China) (2. Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China)

關鍵詞:

氮化鎵; V形坑缺陷; 非輻射復合; 光電性能

Keywords:

GaN; V-shaped pit defects; non-radiative recombination; optical and electrical property

分類號:

TN311+.5

DOI:

10.7502/j.issn.1674-3962.201906042

文獻標志碼:

A

摘要:

自低溫AlN、GaN形核技術和高溫熱退火技術實現了外延高質量GaN薄膜和激活p型GaN受主以來，GaN基光電器件得到了迅猛發展。但是，GaN基光電器件依然存在諸多基礎性問題，特別是基于異質襯底外延的GaN基LED外延層中的位錯密度高達108 cm-2，內量子效率卻超過50%。V形坑是GaN基LED外延層中一種常見的倒金字塔缺陷，6個側面與c面的夾角均為62°。基于V形坑缺陷對LED光電性能影響的研究成果，介紹了V形坑中側壁量子阱屏蔽位錯理論：側壁量子阱的In含量較低，其勢壘高度大于c面量子阱，故在穿透位錯周圍形成了高勢壘，阻擋載流子被非輻射復合中心所捕獲。此外，還綜述了V形坑缺陷的形成機理、附近區域的發光特性、對LED電學特性的影響以及通過優化V形坑調控LED光電性能的研究。

Abstract:

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 108 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�瞫haped 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.