Low-temperature-grown GaAs: Modeling of transient reflectivity experiments

A simple nonradiative Shockley-Read-Hall recombination model is used to interpret transient reflectivity and midinfrared transmission experiments of low-temperature-grown GaAs (LT-GaAs) materials annealed under various conditions of temperature and duration. The model introduces two main parameters, namely the deep-donor (NDD) and the acceptor (NA) concentrations in the GaAs matrix, to explain all observed behaviors coherently with other results in the literature. A precise study of the different parameters (pump wavelength and power, NDD, NA, etc.) is performed using our model. The introduction of growth and anneal-related parameters, such as NA and NDD, allows a good understanding of LT-GaAs. These results demonstrate the importance of acceptor densities in the dynamic properties.