Atomistic simulation of random alloy fluctuations in InGaN/GaN nanowires

Abstract

In this work we present a theoretical study of the effect of random alloy fluctuations in a InGaN inclusion embedded in a GaN nanowire (NW) LED on the electronic and optoelectronic properties. The calculations are based on an empirical tight-binding (ETB) model, while strain is calculated with a valence force field (VFF) method. Energy gaps distributions are obtained and an optical spectral broadening of the cumulative spectra is found, due to alloy fluctuations. A correlation between ground state transition energies and optical strengths has been found, with Virtual Crystal Approximation (VCA) clearly overestimating random mean results.