Carrier transport barrier in AlGaN-based deep ultraviolet LEDs on offcut sapphire substrates  

作　　者：陈秋爽 陈荔 陈聪 高歌 郭炜 叶继春 Qiushuang Chen;Li Chen;Cong Chen;Ge Gao;Wei Guo;Jichun Ye(Ningbo Institute of Materials Technology and Engineering,Ningbo 315201,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Ningbo Institute of Materials Technology and Engineering,Ningbo 315201,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Optics Letters》2024年第2期148-158,共11页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.62104233);the Natural Science Foundation of Ningbo(No.2022J298);the Zhejiang Provincial Natural Science Foundation(No.LQ21F040004);the Ningbo Innovation 2025 Major Project(No.2021Z082)。

摘　　要：AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut sample.Yet,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°ones.Theoretical calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich stripes.Ga-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.

关 键 词：carrier localization step-bunching potential barrier offcut substrate DUV LEDs 

分 类 号：TN312.8[电子电信—物理电子学]