Fabrication, annealing, and regrowth of wafer-scale nanoporous GaN distributed Bragg reflectors

摘要

A wafer-scale distributed Bragg reflector (DBR), which consists of perfectly lattice-matched polar (0001) GaN and nanoporous GaN layers, was fabricated by electrochemical etching method in an oxalic acid solution, presenting high-reflectivity (90%) and wide spectral stop-band width (similar to 80 nm). Annealing of the DBR at 950 degrees C leads to a significant enhancement in the peak reflectivity (95%) due to the mass transport process. According to the above mentioned research, InGaN-based light emitting diodes (LEDs) were regrown on the DBR templates. The photoluminescence intensity of the LED structure on the etched template was four times higher than for standard LED. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.