Abstract

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 In_xGa_1-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.

© 2019 Chinese Laser Press

Quantum barriers with a polarization self-screening effect for GaN-based VCSELs to increase the electron-hole stimulated recombination and output performance

Yuanbin Gao, Chunshuang Chu, Sheng Hang, Yonghui Zhang, Zi-Hui Zhang, and Jianwei Zhou
Opt. Mater. Express 11(12) 3984-3995 (2021)

GaN-based ultraviolet light-emitting diodes with AlN/GaN/InGaN multiple quantum wells

Hung-Ming Chang, Wei-Chih Lai, Wei-Shou Chen, and Shoou-Jinn Chang
Opt. Express 23(7) A337-A345 (2015)

A PN-type quantum barrier for InGaN/GaN light emitting diodes

Zi-Hui Zhang, Swee Tiam Tan, Yun Ji, Wei Liu, Zhengang Ju, Zabu Kyaw, Xiao Wei Sun, and Hilmi Volkan Demir
Opt. Express 21(13) 15676-15685 (2013)

Step-type quantum wells with slightly varied InN composition for GaN-based yellow micro light-emitting diodes

Hua Shao, Chunshuang Chu, Chia-Ming Chuang, Sheng Hang, Jiamang Che, Jianquan Kou, Kangkai Tian, Yonghui Zhang, Quan Zheng, Zi-Hui Zhang, Qing Li, and Hao-Chung Kuo
Appl. Opt. 60(11) 3006-3012 (2021)

On the electric-field reservoir for III-nitride based deep ultraviolet light-emitting diodes

Zi-Hui Zhang, Luping Li, Yonghui Zhang, Fujun Xu, Qiang Shi, Bo Shen, and Wengang Bi
Opt. Express 25(14) 16550-16559 (2017)