Electron localization in a nondegenerate semiconductor with a random potential due to charged impurities

The saturation of the electron mobility, as determined according to the magnetoresistance, was observed in a semiconductor with a large-scale potential due to charged impurities. It was shown that the saturation is due to the existence of a quantum mobility threshold. A negative magnetoresistance of nondegenerate electrons, which is due to the suppression of quantum interferences corrections to the conductivity by the magnetic field, was found. The magnitude of these effects near the mobility threshold was explained by the absence of short, closed, electronic trajectories in the large-scale potential. A relation was established between the amplitude of the random potential and the saturated values of the mobility and the quantum corrections to the conductivity. (C) 2000 MAIK "Nauka/Interperiodica".