Intensity Dependent Minority-Carrier Lifetime in III-V Semiconductors Due to Saturation of Recombination Centers

The minority-carrier lifetime has been measured by time-resolved photoluminescence in a variety of III-V epitaxial material including GaAs and Al_xGa_1-xAs. In cases where Shockley-Read-Hall recombination is dominant, the measured lifetimes are dependent upon the intensity of the excitation source. These lifetime effects can be described by a Shockley-Read-Hall model that includes the injection dependence of the recombination. As the lifetimes increase with the injection level, we describe the effects as the saturation of recombination centers.