Exponential thermal emission transients from DX centers in heavily Si-doped GaAs

Abstract

The kinetics for the thermal emission of electrons from DX levels are shown to be exponential in heavily Si-doped GaAs. Isothermal voltage transients, obtained at constant capacitance, show a perfect exponential behavior. In contrast, a clear deviation from a single exponential function is observed when the transients are recorded at constant voltage, due to the nonuniform doping profile in these structures. The exponential emission kinetics seen in GaAs support the proposal that nonexponential emission kinetics observed at constant capacitance in AlxGa1-xAs are due to different emission rates for DX levels having different local atomic configurations in the alloy.