Efficiency droop in InGaN/GaN-based LEDs with a gradually varying In composition in each InGaN well layer  

作　　者：Shang-Da Qu Ming-Sheng Xu Cheng-Xin Wang Kai-Ju Shi Rui Li Ye-Hui Wei Xian-Gang Xu Zi-Wu Ji 屈尚达;徐明升;王成新;时凯居;李睿;魏烨辉;徐现刚;冀子武(School of Microelectronics,Institute of Novel Semiconductors,Shandong University,Jinan 250100,China;Shandong Inspur Huaguang Optoelectronics Co.,Ltd.,Weifang 261061,China)

机构地区：[1]School of Microelectronics,Institute of Novel Semiconductors,Shandong University,Jinan 250100,China [2]Shandong Inspur Huaguang Optoelectronics Co.,Ltd.,Weifang 261061,China

出　　处：《Chinese Physics B》2022年第1期585-589,共5页中国物理B（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.51872167 and 51672163);the Major Science and Technology Innovation Project of Shandong Province,China(Grant No.2019JZZY010210).

摘　　要：Temperature-dependent and driving current-dependent electroluminescence spectra of two different InGaN/GaN multiple quantum well structures SA and SB are investigated,with the In composition in each well layer(WL)along the growth direction progressively increasing for SA and progressively decreasing for SB.The results show that SB exhibits an improved efficiency droop compared with SA.This phenomenon can be explained as follows:owing to the difference in growth pattern of the WL between these two samples,the terminal region of the WL in SB contains fewer In atoms than in SA,and therefore the former undergoes less In volatilization than the latter during the waiting period required for warming-up due to the difference in the growth temperature between well and barrier layers.This results in SB having a deeper triangular-shaped potential well in its WL than SA,which strongly confines the carriers to the initial region of the WL to prevent them from leaking to the p-GaN side,thus improving the efficiency droop.Moreover,the improvement in the efficiency droop for SB is also partly attributed to its stronger Coulomb screening effect and carrier localization effect.

关 键 词：INGAN/GAN asymmetric triangular multiple quantum wells structural and electroluminescence properties efficiency droop 

分 类 号：TN386[电子电信—物理电子学]