Structural and Optical Characterization of InGaN/GaN Based Quantum Well Structures Grown by MOCVD

Abstract

The InGaN/GaN based Quantum Well structures were grown on c-plane sapphire substrate using metal-organic chemical vapor deposition. Crystalline quality has been investigated using High-resolution X-ray diffraction (HRXRD) analysis and total dislocation densities of screw and edge types in the GaN epilayer have been calculated. The thickness and indium composition of the InGaN was determined by HRXRD. From simulation fit, the composition of indium was found to be 12 and 15% and InGaN thickness was 5 nm. The pseudomorphic growth is observed for InGaN layers as confirmed by X-ray reciprocal space mapping. Room-temperature time-resolved photoluminescence, photoluminescence measurements have been performed on InGaN/GaN based Quantum Well Structures. The photoluminescence intensity and wavelength was found to get enhanced. Time-resolved photoluminescence measurement revealed interesting observation of longer (392 ps) decay time for the InGaN (5 nm)/GaN QW structures.