Electric field induced recombination centers in GaAs

We investigated the lateral electric field effect in a GaAs/AlGaAs single quantum well and in AlGaAs and GaAs single layers. We observed the quenching of photoluminescence spectra at low temperatures even when the electric field was much lower than that required for the dissociation of the excitons. To explain this phenomenon we propose a model of new recombination center formation by considering the displacement of charged atoms. We also performed theoretical calculations. By ab initio calculations, we found that a meta-stable state exists when negatively charged Ga atoms are displaced to the interstitial sites. The calculated potential barrier height from the stable state to the meta-stable state was as high as 0.5 eV. However, the meta-stable to stable transition barrier height was only 0.05 eV. These results are consistent with the experimental results.