Thermoelectric properties of multicomponent solid solutions based on bismuth and antimony chalcogenides with n-type conduction in the region of impurity and mixed conduction

The thermoelectric properties of Bi2−xSbxTe3 − y − zSeySz solid solutions are studied in the temperature range 300–450 K. It is shown that, as the number of atoms involved in substitutions in both sublattices during the formation of a solid solution increases, the maximum in the temperature dependence of the thermopower coefficient and the minimum in the temperature dependence of the thermal conductivity shift toward higher temperatures as a result of an increase in the band gap. As the charge carrier concentration in the sample of a solid solution increases, the onset of mixed conduction shifts toward higher temperatures, which leads to an additional decrease in the thermal conductivity at a fixed temperature. The observed temperature dependences of the thermoelectric properties of the Bi2 − xSbxTe3 − y − zSeySz solid solutions bring about a shift of the maximum in the thermoelectric efficiency toward higher temperatures as the number of atoms involved in the substitution increases.