Metalorganic chemical-vapor deposition of high-reflectance III-nitride distributed Bragg reflectors on Si substrates

TL;DR

This paper demonstrates the successful growth of high-reflectance III-nitride distributed Bragg reflectors on silicon substrates using MOCVD, achieving over 96% reflectance in the blue-green spectrum, enabling potential optoelectronic applications.

Contribution

First demonstration of high-reflectance AlN/GaN DBRs on Si substrates with over 96% reflectance in the visible spectrum.

Findings

Achieved >96% reflectance for AlN/GaN DBRs

Grew crack-free GaN cap layers on DBRs

Demonstrated strain-free GaN cap layers despite substrate mismatch

Abstract

High-reflectance group III-nitride distributed Bragg reflectors (DBRs) were deposited by MOCVD on Si (111) substrates. A reflectance greater than 96% was demonstrated for the first time for an AlN/GaN DBR with a stop-band centered in the blue-green range of the visible spectrum. Crack-free GaN cap layers were grown on the DBR structures to demonstrate the opportunity to build III-nitride optoelectronic devices in this material. The DBR structure was under significant strain due to growth on a mismatched substrate although the GaN cap layer was shown to be strain free.