Ab-initio study of Seebeck coefficient of p-doped PbTe

Abstract

Using density functional theory electronic structure calculations and semi-classical transport theory in relaxation time approximation we compute transport properties of p-doped PbTe. To avoid possible errors due to rigid band approximation (RBA) we use supercell model of doped crystal and tune carrier concentration explicitly by portion of impurity atoms. In such a way we verify the validity of RBA. We considered Na and Tl dopants. The usage of supercell model instead of RBA brings the results closer to the experiment. The possible influence of resonant states on transport properties is discussed.