Theoretical study of thermoelectric properties of MoS2

Abstract

We systematically studied the thermoelectric properties of MoS2 with doping based on the Boltzmann transport theory and first-principles calculations. We obtained an optimal doping region (around 1019 cm−3) for thermoelectric properties along in-plane and cross-plane directions. MoS2 in the optimal doping region has a vanishingly small anisotropy of thermopower possibly due to the decoupling of in-plane and cross-plane conduction channels, but big anisotropies of electrical conductivity σ and electronic thermal conductivity κe arising from the anisotropic electronic scattering time. The κe is comparable to the lattice counterpart κ1 in the plane, while κ1 dominates over κe across the plane. The figure of merit ZT can reach 0.1 at around 700 K with in-plane direction preferred by doping.