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

N/GaN multiple quantum wells grown by MOCVD oversapphire and bulk GaN substrates. High excitation conditions enabled usto achieve a screening of the built-in fleld by free carriers. This allowed forthe evaluation of the in°uence of band potential °uctuations due to thevariation in In-content on e–ciency of spontaneous and stimulated emission.InGaN/GaN multiple quantum wells grown on bulk GaN substrate exhibit asigniflcantly lower stimulated emission threshold and thus enhanced lateralemission. Transient and dynamic properties of luminescence indicate asigniflcant reduction in compositional disorder in homoepitaxially grownstructures.PACS numbers: 78.45.+h, 78.47.+p, 78.67.De