Enhanced external quantum efficiencies of AlGaN-based deep-UV LEDs using reflective passivation layer

• Published in: Optics express Vol. 29; no. 23; pp. 37835 - 37844
• Main Authors: Lin, Su-Hui, Tseng, Ming-Chun, Peng, Kang-Wei, Lai, Shouqiang, Shen, Meng-Chun, Horng, Ray-Hua, Lien, Shui-Yang, Wuu, Dong-Sing, Kuo, Hao-Chung, Wu, Tingzhu, Chen, Zhong
• Format: Journal Article
• Language: English
• Published: 08.11.2021
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.441389

In this study, deep ultraviolet light-emitting diodes (DUV-LEDs) with a reflective passivation layer (RPL) were investigated. The RPL consists of HfO 2 /SiO 2 stacks as distributed Bragg reflectors, which are deposited on two DUV-LEDs with different p -GaN thicknesses. The RPL structure improved the external quantum efficiency droops of the DUV-LEDs with thick and thin p -GaN, thereby increasing their light output power by 18.4% and 39.4% under injection current of 500 mA and by 17.9% and 37.9% under injection current of 1000 mA, respectively. The efficiency droops of the DUV-LEDs with and without the RPL with thick p -GaN were 20.1% and 19.1% and with thin p -GaN were 18.0% and 15.6%, respectively. The DUV-LEDs with the RPL presented improved performance. The above results demonstrate the potential for development of the RPLs for DUV-LED applications.