Exciton localization is studied with time-resolved photoluminescence (PL) i
n Cd1-xMgxTc epilayers. The energy relaxation rate of excitons is found to
be energy dependent and reduces drastically below an effective excitonic mo
bility edge. This particular property results in the saturation of the PL i
ntensity rise time below the mobility edge and a two-exponential decay for
the PL intensity and the energy relaxation of the excitons. (C) 2000 Elsevi
er Science B.V. All rights reserved.