ON THE METASTABILITY OF THE EL2 DEFECT IN PLASTICALLY DEFORMED GAAS

DLTS spectra and transients of photocapacitance quenching under lambda equals 1. 06 mu m photoexcitation of the EL2 defect were investigated in GaAs crystals subjected to plastic deformation. The concentration of EL6 traps increased, and the quenching became slower and non-exponential, after the sample deformation. It is argued that the deformation-induced EL6 traps in the vicinity of EL2 open a new channel for the deexcitation of EL2: phonon assisted electron tunneling from EL2 to EL6, which diminishes the transformation rate of EL2 into the metastable rate. EL6 is assigned to the isolated As//G//a antitisite defect.