The Thermoelectric Figure of Merit in the Mixed Crystal System p‐(Bi 1− x Sb x ) 2 Te 3

The figure of merit Z is a measure for the effectiveness of the thermoelectric material p‐(Bi 1− x Sb x ) 2 Te 3 and depends on the valence band structure, the charge carrier scattering, the lattice thermal conductivity, and the free carrier density. It is shown that crystals with the composition x = 0.75 are favoured by the band structure to have the highest figure of merit in this mixed crystal series. In the frame of a consistent model for the electronic structure the theory—experiment comparison gives good quantitative agreement for the Z ( S )‐plot in terms of effective masses and lattice thermal conductivity over a wide range of the Seebeck coefficient S .