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 δ-doped In0.2Ga0.8As/GaAs quantum wells using the PL up-conversion technique. The luminescence spectrum of this sample displayed the characteristic features of the Fermi edge singularity. The temporal 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 that the radiative decay time decreases dramatically with increasing temperature (τr=45 ps at T=125 K) which, we believe, is the result of the smearing of the Fermi edge and the delocalization of the holes that are responsible for the luminescence.