Enhanced light extraction efficiency of micro-ring array AlGaN deep ultraviolet light-emitting diodes. (25th August 2017)

• Record Type: Journal Article
• Authors: Fayisa, Gabisa Bekele; Lee, Jong Won; Kim, Jungsub; Kim, Yong-Il; Park, Youngsoo; Kim, Jong Kyu
• Is Part Of: Japanese journal of applied physics. Volume 56:Number 9(2017)
• Publication Date: 2017-08-25
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.56.092101
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: An effective approach to overcome inherently poor light extraction efficiency of AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) is presented. We demonstrated the 5 × 5 array micro-ring DUV LED having an inclined sidewall at the outer perimeter and a p-GaN-removed inner circle of the micro-ring, together with MgF2 /Al omnidirectional reflectors. The micro-ring array DUV LED shows remarkably higher light output power by 70% than the reference, consistent with the calculated result, as well as comparable turn-on and operational voltages, which are attributed to the effective extraction of strong transverse-magnetic polarized anisotropic emission and the reduction of the absorption loss by the p-GaN contact layer, simultaneously.