Photoluminescence excitonic linewidth in GaAsN alloys

We have calculated the variation of the photoluminescence excitonic linewidth, defined as the full width at half maximum, due to composition fluctuations as a function of nitrogen composition in completely random GaAs1-xNx alloys. We have considered the effects of a constant and of the composition dependent bowing parameter (and, thus, the energy band gap) on the excitonic linewidth. We have used two different recently proposed variations of the conduction electron mass with nitrogen composition. We have considered both the free and localized excitons. We find that the behavior of excitonic linewidth as a function of nitrogen composition, using two different bowing parameters, is qualitatively and quantitatively quite different. (C) 2003 American Institute of Physics.