Improvement of interface morphology and luminescence properties of InGaN/GaN multiple quantum wells by thermal annealing treatment

We have demonstrated the role of thermal annealing treatment after InGaN quantum well layer growth to improve the interface morphology and luminescence properties of InGaN/GaN multiple quantum wells (MQWs). X-ray diffraction and transmission electron microscope analyses reveal that better structural properties are achieved by appropriately increasing the ramp-up time as well as relatively decreasing the annealing temperature as the interface quality of MQWs is improved. Moreover, the photoluminescence (PL) and electroluminescence (EL) measurements confirm the higher crystal quality and optical properties of InGaN/GaN MQWs. The reason may be the redistribution of indium atoms improves the homogeneity of localized states in MQWs, and the In-rich clustering behavior is obviously alleviated. This annealing method is feasible and can lead to obtaining high-performance semiconductor optoelectronic devices.