Higher output power of near-ultraviolet LED grown on GaN substrate with back-side etching
Abstract
The 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)