DYNAMICS OF PHOTOEXCITED HOLES IN N-DOPED INGAAS GAAS SINGLE-QUANTUM-WELL/

We have measured the temporal evolution of the photoluminescence (PL) of a Si delta-doped In0.2Ga0.8As/GaAs quantum wells using the PL up-co nversion technique. The luminescence spectrum of this sample displayed the characteristic features of the Fermi edge singularity. The tempor al evolution of the luminescence is described in terms of the dynamics of the hole population. From the experiments, we have determined the effective hole capture time (15 ps), the interband relaxation time (3 ps), and the radiative decay time (>1 ns) at T = 8 K. We have found th at the radiative decay time decreases dramatically with increasing tem perature (tau(r) = 45 ps at T = 125 K) which, we believe, is the resul t of the smearing of the Fermi edge and the delocalization of the hole s that are responsible for the luminescence. (C) 1997 American Institu te of Physics.