Effects of a finite coherence on impurity trapping of quasi-free excitons and electrons

The effects of weak scattering by the medium on the rate of impurity trapping for partially coherent excitons and electrons are studied in 1-D and 3-D lattices. It was found that the cage effect does not alter the asymptotic (t→∞) rate expression for 1-D, but modifies the asymptotic rate in 3-D in such a way that the rate is inversely proportional to the diffusion coefficient in the region of large coherence length and becomes proportional to the diffusion coefficient when the coherence length becomes of the order of the lattice constant. Relevant experiments are discussed.