Theoretical study of thermoelectric properties of MoS₂

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 κ_e arising from the anisotropic electronic scattering time. The κ_e is comparable to the lattice counterpart κ_l in the plane, while κ_l dominates over κ_e across the plane. The figure of merit ZT can reach 0.1 at around 700 K with in-plane direction preferred by doping.