Effect of exciton localization on the quantum efficiency of GaN/(In,Ga)N multiple quantum wells

Abstract

Cathodoluminescence spectroscopy is used to investigate the dependence of transition energy and quantum efficiency on both temperature and excitation density in GaN/(In,Ga)N multiple quantum well structures with different well widths grown by molecular beam epitaxy. A coupled rate-equation model is introduced to explain the experimental results. Polarization field screening has been incorporated in a realistic manner by solving these coupled rate-equations self-consistently along with the Schrödinger and Poisson equations. Our study suggests that exciton localization increases the internal quantum efficiency significantly.