Characterization of InGaN/GaN Quantum Well grown on GaN microdisk using $\gamma $-LiAlO$_{2}$ substrate by Plasma-assisted Molecular Beam Epitaxy*

The InGaN/GaN quantum wells grown on GaN microdisks by plasma-assisted molecular beam epitaxy (PAMBE) have been investigated. The optical properties and micro-structure of InGaN/GaN quantum wells were studied by Cathodoluminescence (CL) and transmission electron microscope (TEM). According to the observation of high-resolution TEM, we obtained the high quality of InGaN/GaN quantum wells grown on GaN micro-disk. The In-ratio (x) of In$_{x}$Ga$_{1-x}$N is $\sim $8{\%} determined by the measurement of energy-dispersive X-ray spectroscopy (EDX). The optical gap of In$_{0.08}$Ga$_{0.92}$N was measured to be $\sim $3eV determined by CL measurement, which is consistent with the calculation of bowing parameters and the measurement of EDX.