Transport properties and electronic structure of glasses in the arsenic-selenium system

Abstract

Data are presented on the transport properties of arsenic-selenium glasses containing 30-50% As. The hole carrier drift mobility and d.c. conductivity have been studied as functions of composition, temperature, and applied electric field. The magnitude and activation energy of both the mobility and the conductivity exhibit extrema close to the stoichiometric As₂Se₃ composition. These and other data obtained are examined in terms of possible transport mechanisms for the glasses. It is concluded that the materials possess several relatively discrete sets of trapping centres above the valance band mobility edge, and that these limit the motion of free hole carriers moving close to the mobility edge.