Electronic structure and thermoelectric properties of PbTe1−xSex from first-principles calculations

Abstract

Electronic structures and thermoelectric transport properties of a series of PbTe1−xSex solid solutions have been investigated using density functional theory and Boltzmann transport equation with constant relaxation time approximation. The evolution of the band structure with the variation of Se concentration has been studied systematically. It has been found out that the Seebeck coefficients and power factors of p-type PbTe1−xSex solid solutions decrease continuously with increasing Se concentration, which is mainly due to the higher the Se concentration, the flatter the density of states near the edge of the valence band. The dependence of the thermoelectric transport coefficients on carrier concentration and temperature was discussed in detail. Our studies provide a guidance for future experiments to search high-efficiency p-type PbTe1−xSex solid solutions.