Quantitative interpretation of the phonon-assisted redistribution processes of excitons in Zn1-xCdxSe quantum islands

We present a quantitative interpretation of the anomalous temperature behavior-the so-called S-shape dependence-of the photoluminescence (PL) in quantum films containing nanoislands. Experimental data for CdSe/ZnSe samples are modeled using Monte Carlo simulations of the involved relaxation mechanisms and thus providing a realistic picture of the exciton kinetics. We are able to reproduce simultaneously the temperature dependence of the PL maximum and of the full width at half maximum of the PL with good accuracy. We deduce information about the distribution of the localization centers and identify hopping processes between spatially separated states within one island.