Photoluminescence of native-like shallow acceptor generated during annealing of semi-insulating GaAs

The new PL lines at 1.496 eV and 1.192 eV related to the conduction band-to-acceptor and donor-to-acceptor transitions, respectively were observed in the PL spectrum of bulk undoped LEC SI-GaAs and in some SI-GaAs crystals grown by the VGF technique. No correlation between these PL lines and the shallow residual acceptor impurity was stated. The acceptor responsible for these PL lines can be created during rapid cooling from temperature T>1000/spl deg/C, so it seems to be a native-like complex. It is difficult to present a detailed model of this defect. However, one can conclude that a native-like shallow acceptor can be present in as grown undoped LEC SI-GaAs crystals when the cooling of the crystal in the puller occurs quickly.