Temperature dependence of mobilities and carrier concentrations in semi-insulating GaAs

Abstract

The temperature behavior of electron and hole mobilities and carrier concentrations was measured in p-type Cr doped semi-insulating GaAs. The above quantities were determined by measuring at a given temperature the photomagnetoresistance and photo-Hall effect vs magnetic field intensity. A minimum of hole concentration is observed at 210-225 K. The electron concentration either remains constant below 190-200 K or it rises again at lower temperatures. The mobilities of both carriers show a maximum at almost the same temperatures with those where the behavior of n and p changes. We try to explain the above on the basis of radiative recombination and impurity conduction. © 1980