InGaN light-emitting diode structure on a photoelectrochemical treated GaN: Si layer

摘要

InGaN/GaN multiple-quantum-wells light-emitting diode (MQW-LED) structure was grown on a photoelectrochemical (PEC) treated n-type GaN:Si layer in deionized water. The PEC treated GaN:Si layer consisted of a nanoporous GaN:Si layer with a multiple-air-gaps (MAG) structure and the native GaOx layers that acted as submicro-masks for the epitaxial lateral overgrowth (ELOG) process. The threading dislocation density of the MAG-LED structure is seen reduced on the cross-sectional transmission electron microscopy micrographs. The photoluminescence spectrum has a 4.5nm wavelength blueshift phenomenon and a 2.0 times peak intensity enhancement in the MAG-LED structure (compared to a standard-LED) that is caused by a partially reduced piezoelectric field and an increasing light extraction process. The higher internal quantum efficiency and the higher light extraction process were observed in the MAG-LED structures by adding large volume of native GaOx layers and PEC treated multiple-air-gaps layers.