Photoluminescence properties of etched GaN-based LEDs via UV-assisted electrochemical etching

Abstract A GaN-based light emitting diode (LED) with an InGaN/GaN multiple quantum well (MQW) structure was electrochemically etched in an oxalic acid solution under ultraviolet (UV) light and fabricated into nanoporous structure for the first time. Compared to that of the as-grown GaN-based LED, photoluminescence (PL) emission of the etched LEDs shows (i) a marked blue-shift which is ascribed to a stress relaxation and a relative decrease of indium (In) component in the MQW layer, (ii) a two-fold enhancement of PL intensity which results from the increase of light-extracting surface area, light-guiding effect, and internal quantum efficiency.