Tunable thermoelectric properties of SnS2 under high pressure at room temperature

In this paper, we study the structural, electronic, vibrational, thermoelectric and elastic properties of fin disulfide (SnS2) using first principles density functional theory calculations in the pressure range 0 <= p <= 5 GPa. The variation of lattice constant along c-axis is found to be higher than that along the c-axis which significantly affects the properties. The electronic band gap is observed to decrease with the applied pressure. The Raman shift of E-g and A(1g) modes increases with applied pressure. Furthermore, SnS2 remains dynamically stable up to 5 GPa. Thermoelectric properties such as thermopower (S), electrical conductivity (sigma), power factor (S-2 sigma) show anisotropy. While the in-plane direction is more dominant at ambient pressure, the out-of-plane is more dominant with the increase in pressure. The calculated power factor is higher in the hole concentration than the electron concentration in the defined pressure range at room temperature. This suggests that SnS2 could be an excellent candidate material of p-type thermoelectric under high pressure conditions.