Dynamics of Exciton Recombination in II-VI Semiconductor Quantum Wells

We have studied the temporal evolution of the inhomogeneously broadend exciton emission band to obtain information about the process of exciton localization in ZnCdSe/ZnSe and ZnSe/ZnMnSe quantum well structures. The observed behavior can be described with quantitative agreement by theoretical calculations taking into account the exciton center-of-mass motion in a disordered potential being Gauss distributed and correlated over distances of the exciton Bohr radius. As predicted by the theory a nearly linear increase of the exciton life-time is observed between 5 K and 40 K for the ZnCdSe/ZnSe structure.