Improving hole injection from p-EBL down to the end of active region by simply playing with polarization effect for AlGaN based DUV light-emitting diodes
Danyang Zhang,
Chunshuang Chu,
Kangkai Tian,
Jianquan Kou,
Wengang Bi,
Yonghui Zhang,
Zi-Hui Zhang
Affiliations
Danyang Zhang
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Chunshuang Chu
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Kangkai Tian
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Jianquan Kou
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Wengang Bi
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Yonghui Zhang
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
Zi-Hui Zhang
School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, 5340 Xiping Road, Beihen District, Tianjin 300401, People’s Republic of China
In this work, we simply take advantage of the polarization effect to efficiently improve the hole injection from the p-type electron blocking layer (p-EBL) to the end of the active region for AlGaN based deep ultraviolet light emitting diodes (DUV LEDs). By properly increasing the AlN composition of AlGaN quantum barriers, a smaller positive polarized charge density at the last quantum barrier/p-EBL interface can be obtained, which correspondingly leads to the suppressed hole depletion and the reduced hole blocking effect in the p-EBL. Meanwhile, we properly increase the quantum well thickness so that the polarized electric field can even more accelerate the holes, and this will homogenize the hole distribution more across the MQWs. Therefore, the external quantum efficiency for DUV LEDs can be enhanced.
