Performance-Enhanced 365 nm UV LEDs with Electrochemically Etched Nanoporous AlGaN Distributed Bragg
Authors: Lu, XD; Li, J; Su, K; Ge, C; Li, ZC; Zhan, T; Wang, GH; Li, JM
NANOMATERIALS
Volume: 9 Issue: 6 Published: JUN 2019 Language: English Document type: Article
DOI: 10.3390/nano9060862
Abstract:
A 365-nm UV LED was fabricated based on embedded nanoporous AlGaN distributed Bragg reflectors (DBR) by
electrochemical etching. The porous DBR had a reflectance of 93.5% at the central wavelength of 365 nm;
this is the highest value of porous AlGaN DBRs below 370 nm which has been reported so far. An
innovative two-step etching method with a SiO2 sidewall protection layer (SPL) was proposed to protect
the n-AlGaN layer and active region of UV LED from being etched by the electrolyte. The DBR-LED with SPL
showed 54.3% improvement of maximal external quantum efficiency (EQE) and 65.7% enhancement of optical
power at 100 mA without any degeneration in electrical properties, compared with the un-etched standard
LED sample. This work has paved the way for the application of electrically-pumped UV LEDs and VCSELs
based on nanoporous AlGaN DBRs.
Full Text: https://www.mdpi.com/2079-4991/9/6/862