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In-depth insights into polarization-dependent light extraction mechanisms of AlGaN-based deep ultraviolet light-emitting diodes

Authors :
Tongchang Zheng
Changjie Zhou
Huili Zhu
Qiubao Lin
Lan Yang
Duanjun Cai
Junyong Kang
Source :
Optics Express. 31:15653
Publication Year :
2023
Publisher :
Optica Publishing Group, 2023.

Abstract

The AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) dominated by transverse-magnetic (TM) polarized emission suffer from extremely poor light extraction efficiency (LEE) from their top surface, which severely limits the device performance. In this study, the underlying physics of polarization-dependent light extraction mechanisms of AlGaN-based DUV LEDs has been explored in depth via simple Monte Carlo ray-tracing simulations with Snell's law. It is especially worth noting that the structures of the p-type electron blocking layer (p-EBL) and multi-quantum wells (MQWs) have a significant impact on light extraction behavior, especially for TM-polarized emission. Thus, an artificial vertical escape channel (named GLRV) has been constructed to efficiently extract the TM-polarized light through the top surface, by adjusting the structures of the p-EBL, MQWs, sidewalls, and using the adverse total internal reflection in a positive manner. The results show that the enhancement times of the top-surface LEE is up to 18 for TM-polarized emission in the 300 × 300 µm2 chip comprising a single GLRV structure, and further increases to 25 by dividing this single GLRV structure into a 4 × 4 micro-GLRV array structure. This study provides a new perspective for understanding and modulating the extraction mechanisms of polarized light to overcome the inherently poor LEE for the TM-polarized light.

Details

ISSN :
10944087
Volume :
31
Database :
OpenAIRE
Journal :
Optics Express
Accession number :
edsair.doi...........f97ba0b22a2acd129c400f3fdfb0e220
Full Text :
https://doi.org/10.1364/oe.487207