Surface conductance in semi-insulating GaAs

Abstract

The authors present the results of measuring the temperature dependence of the surface conductance in semi-insulating GaAs samples with differently treated surfaces. Three transport mechanisms on the surface have been observed, namely the activated, hopping-like and Berthelot mechanisms. It is shown that the subsurface layer plays an important role in the manifestation of the individual mechanisms. The above behaviour is accounted for by a simple model.