Investigation of the Weak‐Field Charge Transport in Semiconducting V2—VI3 Compounds with Trigonal Symmetry I. Expanded Model for the Transport Coefficients

In the series of trigonal V2—VI3 semiconductorsBi2Te3, Bi2Se3, and Sb2Te3 up to now it has not been succeeded to interpret the temperature dependence of the weak—field charge transport for Sb2Te3 single crystals in terms of a physical relevant model with reasonable semiconductor data. Therefore, an expanded transport model is presented takinginto account nonparabolic manyvalley band structure as well as the simultaneous action of anisotropic mixed charge carrier scattering by acoustical phonons and ionized impurities in the relaxation time approximation. Under these conditions the expressions for the thermoelectric, galvano‐ and thermomagnetic coefficients and the Lorenz numbers are given. These formulas are also valid for Bi2Te3 at pure acoustical mode scattering and for Bi2Se3 at single‐valley band structure.