Diffusion of Si in δ-Doped GaAs Studied by Magneto Transport

We have performed time dependent and temperature dependent annealing experiments on Si-δ-doped GaAs grown at 480 °C. We observed a doping concentration dependent diffusion rate. The increment of the diffusion rate with the doping concentration is thought to be due to self-compensation of the Si-dopant in δ-doped GaAs. This explanation is in agreement with the experimentally observed large degree of self-compensation and the presence of the δ-exiton line in the photoluminescence spectra in samples that are doped above 5–1012 cm-2 and grown at 480 °C.