Electric and thermoelectric properties of (SbSn)xSe100−x chalcogenide glasses

The electric conductivity and thermoelectric power for different compositions of the chalcogenide glasses (SbSn)xSe100−x (x = 4, 8, 12, 16 and 20 at.%) were measured experimentally. The dc conductivity is found to have an Arrhenius behavior in the temperature range (300–450) K with typical activation energies decreasing from 0.87 to 0.74 eV with the SbSn content. The concentrations of charge carriers, as well as their mobility and characteristic relaxation time were deduced in the same temperature range and compositions. The variations of activation energy calculated from measured electric conductivity versus SbSn content are compared to the behavior of calculated half band gap. From the measured Seebeck coefficient, we deduced its specific activation energy and found that it is lower than that related to electric conductivity. This difference is assumed to be the activation energy needed for polaron hopping. The increase in cross-linking with SbSn content is proposed as an explanation for the increase in polaron-hopping activation energy.