Electronic transport in SeTeSb glasses

Measurements of dc electrical conductivity, thermopower, and Hall coefficient are carried out as a function of temperature on a number of SeTe alloys to which various amounts of Sb are added. The transport properties of the SeTeSb glasses are interpreted in the framework of the Mott and Davis model for the band structure of an amorphous semiconductor. Incorporation of increasing amounts of Sb broadens the width of the valence band tail and, hence, enhances the contribution of conduction in localized states. The transport coefficient data seem difficulty to reconcile with the small‐polaron hypothesis.