Luminescence in Highly Excited InGaN/GaN Multiple Quantum Wells Grown on GaN and Sapphire Substrates

Abstract

We report on high-excitation luminescence spectroscopy in In x Ga 1-x N/GaN multiple quantum wells grown by MOCVD over sapphire and bulk GaN substrates.High excitation conditions enabled us to achieve a screening of the built-in field by free carriers.This allowed for the evaluation of the influence of band potential fluctuations due to the variation in In-content on efficiency of spontaneous and stimulated emission.InGaN/GaN multiple quantum wells grown on bulk GaN substrate exhibit a significantly lower stimulated emission threshold and thus enhanced lateral emission.Transient and dynamic properties of luminescence indicate a significant reduction in compositional disorder in homoepitaxially grown structures.