High pressure effect on structure, electronic structure, and thermoelectric properties of MoS2

We systematically study the effect of high pressure on the structure, electronic structure, and transport properties of 2H-MoS2, based on first-principles density functional calculations and the Boltzmann transport theory. Our calculation shows a vanishing anisotropy in the rate of structural change at around 25 GPa, in agreement with the experimental data. A conversion from van der Waals to covalent-like bonding is seen. Concurrently, a transition from semiconductor to metal occurs at 25 GPa from band structure calculation. Our transport calculations also find pressure-enhanced electrical conductivities and significant values of the thermoelectric figure of merit over a wide temperature range. Our study supplies a new route to improve the thermoelectric performance of MoS2 and of other transition metal dichalcogenides by applying hydrostatic pressure.