Epitaxial layers which had been grown under ultra-fast cooling rates were investigated by using deep-level transient spectroscopy and photoluminescence techniques. It was observed that non-equilibrium growth conditions led to the formation of defects which were typical of irradiated material and were related to VAs and AsGa. Irradiation of the layers by laser light with a wavelength of 0.5 resulted in changes in the deep-level transient spectra of GaAs and AlGaAs, and in changes in the photoluminescence spectra of AlGaAs. These changes were related to the optically induced annealing of defects and to the recombination-generation diffusion of impurities; thus leading to the formation of complex arsenide vacancy-donor impurities.

A.V.Abramov, N.G.Deryagin, A.G.Deryagin, V.K.Kuchinsciy, M.M.Sobolev, M.I.Papentsev: Materials Science Forum, 1995, 196-201, 1437-42