Direct measurement of heavy-hole exciton transport in type-II GaAs/AlAs superlattices

We have directly measured the transport of heavy-hole excitons in a type-II GaAs/AlAs superlattice. Our results constitute the first direct confirmation of exciton localization in type-II structures and thermal activation to more mobile states. We have also developed a quantitative model to explain our transport and kinetics results, and have obtained the nonradiative interfacial defect density. © 1993 The American Physical Society.