In this paper we will present our recent work aimed at developing deep ultraviolet light-emitting diodes with emission from 250-280 nm. These devices were fabricated using AlGaN multiple quantum wells that were deposited on basal plane sapphire substrates using low-pressure MOCVD. Innovative MEMOCVD grown AlN buffer layers and AlN/AlGaN superalttices were also employed in the device structures to manage strain and allow the deposition of thick AlGaN layers, which was necessary to reduce the lateral spread resistance. Devices with square, multifinger and micro-LED geometries were fabricated and flip-chip mounted on AlN carriers for improved thermal management and light extraction. We have now succeeded in obtaining devices at 275 and 280 nm with cw powers in excess of 1.5 mW and pulsed powers well over 20 mW. Recently we have also succeeded in obtaining nearly milliwatt powers using an innovative micro-LED design at 250 nm. Now, for the first time, we also present dc operation of micro-pixel design deep UV LED.

Date Published: 20 October 2004
PDF: 7 pages
Proc. SPIE 5530, Fourth International Conference on Solid State Lighting, (20 October 2004); doi: 10.1117/12.567108

Published in SPIE Proceedings Vol. 5530:
Fourth International Conference on Solid State Lighting
Ian T. Ferguson; Nadarajah Narendran; Steven P. DenBaars; John C. Carrano, Editor(s)