Optically induced annneal of GaAs and AlGaAs layers.

GaAs and AlGaAs epitaxial layers, grown under ultra fast cooling rates, have been investigated by DLTS and photoluminescence (PL) measurements. It was observed, that unequilibrium growth conditions lead to formation of defects, which are typical far irradiated GaAs and AlGaAs and are connected with V-As and As-Ga. Irradiation of these layers by laser with wavelength lambda=0.5 mu results in changes of DLTS spectra in GaAs and AlGaAs and in changes of PL spectra in AlGaAs. These changes in DLTS and PL spectra are connected with particle optically induced annealing of defects and with recombination-generation diffusion of impurity, leading to formation of complex arsenide vacancy- donor impurity.