Drift Mobility of Electrons in TlCl

Abstract

The drift mobility of photoelectrons in TlCl has been measured over the temperature range between 90°K and 330°K by a transit time technique in order to study the behavior of finite temperature polarons. The intrinsic mobilities are measured in the whole range of temperature only in zone-refined crystals. They are compared with the theories developed recently for the finite temperature polarons as well as those for the low temperature ones. The agreements are shown to be unsatisfactory. Decrease of the drift mobility at low temperatures as a result of multiple trapping effect due to the presence of shallow traps of 0.05 eV depth is observed in some crystals.