Significantly Increased Luminescence Properties of the Wafer-Scale Mesoporous GaN-Based LEDs with Mesoporous GaN-Distributed Bragg Reflectors

Mesoporous GaN-based multiple quantum wells (MP MQWs) with MP GaN-distributed Bragg reflectors (MP GaN DBRs) are obtained via electrochemical etching in a HNO3 solution. Wafer-scale MP MQWs with MP GaN DBRs have a smooth surface, low root-mean-square roughness (RRMS), and high reflectivity. Then, the p-GaN layer is grown on the MP MQWs with the MP GaN DBR substrate. Compared with as-grown light-emitting devices (AG LEDs), MP LEDs with MP GaN DBRs possess an increased and blue-shifted luminescence emission. The luminescence enhancement results from the reduced density of dislocations of MP MQWs and the highly reflective effect of MP GaN DBRs. Also, the blue shift is due to reduced stress in the MQW layer.