Optical properties of In-rich InGaN/GaN single quantum well structures with high density of clusters

Abstract

An In-rich InGaN/GaN single quantum well structure has been successfully grown by metalorganic chemical vapor deposition. Optical properties were systematically studied by photoluminescence (PL), PL excitation (PLE), selective excitation PL and cathodoluminescence (CL). The PL intensity of the In-rich InGaN structure decreased only by a factor of 17.7 when the temperature increased from 10 K to 300 K, showing a high quantum efficiency. Two different InGaN-related emissions and absorption-edges have been verified by selective excitation PL and PLE. CL observation showed that the epilayer agglomerated together to form clusters due to the large lattice and thermal mismatch and that the two different InGaN emissions originated from spatially different regions.