On the polarization self-screening effect in multiple quantum wells for nitride-based near ultraviolet light-emitting diodes  

作　　者：Kangkai Tian Chunshuang Chu Jiamang Che Hua Shao Jianquan Kou Yonghui Zhang Zi-Hui Zhang Tongbo Wei 田康凯;楚春双;车佳漭;邵华;寇建权;张勇辉;张紫辉;魏同波(Institute of Micro-Nano Photoelectron and Electromagnetic Technology Innovation,School of Electronics and Information Engineering,Hebei University of Technology,Tianjin 300401,China;Key Laboratory of Electronic Materials and Devices of Tianjin,Tianjin 300401,China;State Key Laboratory of Solid-State Lighting,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China)

机构地区：[1]Institute of Micro-Nano Photoelectron and Electromagnetic Technology Innovation,School of Electronics and Information Engineering,Hebei University of Technology,Tianjin 300401,China [2]Key Laboratory of Electronic Materials and Devices of Tianjin,Tianjin 300401,China [3]State Key Laboratory of Solid-State Lighting,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China

出　　处：《Chinese Optics Letters》2019年第12期68-72,共5页中国光学快报（英文版）

基　　金：supported by the Natural Science Foundation of Tianjin City(Nos.16JCYBJC16200 and16JCQNJC01000);the Natural Science Foundation of Hebei Province(No.F2017202052);the Technology Foundation for Selected Overseas Chinese Scholars by the Ministry of Human Resources and Social Security of the People’s Republic of China(No.CG2016008001);the 100-Talent-Plan of Hebei Province(No.E2016100010)

摘　　要：The tilted energy band in the multiple quantum wells（MQWs） arising from the polarization effect causes the quantum confined Stark effect（QCSE） for [0001] oriented III-nitride-based near ultraviolet light-emitting diodes（NUV LEDs）. Here, we prove that the polarization effect in the MQWs for NUV LEDs can be self-screened once the polarization-induced bulk charges are employed by using the alloy-gradient InxGa1-xN quantum barriers. The numerical calculations demonstrate that the electric field in the quantum wells becomes weak and thereby flattens the energy band in the quantum wells, which accordingly increases the spatial overlap for the electron-hole wave functions. The polarization self-screening effect is further proven by observing the blueshift for the peak emission wavelength in the calculated and the measured emission spectra. Our results also indicate that for NUV LEDs with a small conduction band offset between the quantum well and the quantum barrier,the electron injection efficiency for the proposed structure becomes low. Therefore, we suggest doping the proposed quantum barrier structures with Mg dopants.The tilted energy band in the multiple quantum wells(MQWs)arising from the polarization effect causes the quantum confined Stark effect(QCSE)for[0001]oriented Ⅲ-nitride-based near ultraviolet light-emitting diodes(NUV LEDs).Here,we prove that the polarization effect in the MQWs for NUV LEDs can be self-screened once the polarization-induced bulk charges are employed by using the alloy-gradient InxGa1-xN quantum barriers.The numerical calculations demonstrate that the electric field in the quantum wells becomes weak and thereby flattens the energy band in the quantum wells,which accordingly increases the spatial overlap for the electron-hole wave functions.The polarization self-screening effect is further proven by observing the blueshift for the peak emission wavelength in the calculated and the measured emission spectra.Our results also indicate that for NUV LEDs with a small conduction band offset between the quantum well and the quantum barrier,the electron injection efficiency for the proposed structure becomes low.Therefore,we suggest doping the proposed quantum barrier structures with Mg dopants.

关 键 词：POLARIZATION DIODES QUANTUM 

分 类 号：O471.1[理学—半导体物理] TN23[理学—物理]