Effect of V/III variation on the optical properties of GaAs and AlxGa1−xAs grown by metalorganic chemical vapor deposition

A detailed investigation of the effect of the V/III ratio during growth on the optical properties of GaAs and AlGaAs grown by metalorganic chemical vapor deposition is reported, using the low-temperature photoluminescence technique. In the case of GaAs, it was found that the dominant acceptor is carbon and that its concentration decreases monotonically as the As/Ga ratio is increased. For the AlGaAs case, it was found that the concentration of deep impurities increases with decreasing Ga and Al content, but the amount of carbon remains fairly constant.