Growth and Characterization of III-N Ultraviolet Lasers and Avalanche Photodiodes by MOCVD

Abstract

The field of ultraviolet (UV) photonics at wavelengths λ<400nm is an area of increasing practical interest and coherent light sources and fast, sensitive photodetectors are needed for many important applications. The GaN-based near-UV lasers at ∼370nm in this report were epitaxially grown on a c-axis n-type GaN:Si and (0001) sapphire substrates using metalorganic chemical vapor deposition (MOCVD) and fabricated into optically pumped vertical-cavity UV lasers. Similar structures were grown incorporating p-n junctions to created micro-cavity UV LEDs. Also in this work, GaN UV PIPIN avalanche photodiodes (APDs) are grown on “free-standing” (FS) and “bulk” n-type (0001) GaN substrates having low dislocation densities by MOCVD and APDs were fabricated and tested.