Correlating exciton localization with compositional fluctuations in InGaNGaN quantum wells grown on GaN planar surfaces and facets of GaN triangular prisms

We have used spatially and temporally resolved cathodoluminescence (CL) to study the carrier recombination dynamics of InGaN quantum wells (QWs) grown on (0001)-oriented planar GaN and {1 1- 01} -oriented facets of GaN triangular prisms prepared by lateral epitaxial overgrowth in a metal-organic chemical vapor deposition system. The effects of In migration during growth on the resulting QW thickness and composition were examined. We employed a variable temperature time-resolved CL imaging approach that enables a spatial correlation between regions of enhanced exciton localization, luminescence efficiency, and radiative lifetime with the aim of distinguishing between excitons localized in In-rich quantum dots and those in the surrounding Ga-rich QW regions.