Seebeck coefficient and electrical conductivity in p-(Bi1−xSbx)2 Te3 at room temperature

Representative values are presented of Seebeck coefficient S and electrical conductivity σ at room temperature for single-phase crystals oriented perpendicular and parallel to the trigonal c-axis with a large variation of the Fermi level. Except for Sb2Te3 the S–σ dependence of the mixed crystal system can be described by parabolic one-valence band conduction and by dominant acoustical mode scattering with only small variation of values u0(md/m0)3/2 (u0 “classical” mobility; md effective density of state mass). The values of Sb2Te3 show additional to the S anisotropy, as already earlier stated, a deviation from the simple standard model at high values of the electrical conductivity. This can be explained qualitatively by non-parabolic one-valence band conduction with mixed anisotropic scattering.