Defect-enhanced annealing by carrier recombination in GaAs

We have performed a systematic study of carrier injection annealing of the defects introduced by electron irradiation in n-type GaAs in the temperature range 300--355 K and with injected current densities ranging from 0.5 to 2 A?^-2. We first observed that the various defects do not anneal in the same fashion as stated in a previous study. We show that, because the associated activation energies decrease continuously as the injected current increases, the model previously proposed for the enhanced annealing in which the enhancement is induced by the energy which is released when a minority carrier is trapped on the defect site cannot apply. However, this enhanced annealing can be quantitatively understood if the annealing is induced by successive changes of the defect charge state when it traps alternatively minority and majority carriers.