Optically induced regeneration of the stable configuration of the EL2 defect in GaAs

Abstract
Electron paramagnetic resonance measurements on the EL2 defect in semi-insulating GaAs show that after optically induced quenching into the metastable configuration the original stable configuration can be optically regenerated at temperatures below 140 K. We determined the spectral dependence of this regeneration in the 70–140 K temperature range. It is characterized at 90 K by an absorption band centered at (0.8±0.1) eV. However, the spectral dependence is temperature dependent and the thermal activation energy varies with the photon energy.