Higher output power of near‐ultraviolet LED grown on GaN substrate with back‐side etching

Abstract

AbstractThe 405 nm near‐ultra violet (NUV) InGaN/GaN multiple‐quantum‐well light‐emitting diodes (LEDs) grown on GaN substrate with a roughened backside on the N‐face surface of GaN substrate were fabricated through a chemical wet‐etching process to increase light‐extraction efficiency. The stable crystallographic etching planes were formed as the GaN {1011} planes. The back‐side etching NUV LEDs had larger output power than that of conventional NUV‐LEDs, NUV‐LEDs with wider wells, and NUV‐LEDs grown on pattern sapphire substrate.When the NUV LED were operated as a forward current of 20 mA, the increasing output power of back‐side etching NUV LEDs was about 70%, 106%, and 8% than that of conventional NUV‐LEDs, NUV‐LEDs with wider wells, and NUV‐LEDs grown on pattern sapphire substrate (PSS), respectively. This larger enhancement result from the improved light extraction attributed to the different transmittance as hexagonal pyramid on N‐face GaN was etched (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)