Electrodeless wet etching of GaN assisted with chopped ultraviolet light

The electrodeless photoelectrochemical (PEC) wet etching of GaN, photoassisted with chopped ultraviolet light, was investigated. The scanning electron microscopy was used to study the etched surfaces of GaN. It was observed that the rate of recombination of electrons and holes at a dislocation defect was greater than for crystalline GaN, resulting in a rough etched surface with pyramids. A shorter period of chopped UV irradiation was observed to offer a smoother etched surface via a decrease of the carrier recombination in dislocation.