Structural, electronic and thermoelectric properties of bulk and monolayer of Sb^sub 2^Se^sub 3^ under high pressure: By GGA and mBJ approaches

The effects of high pressure on the structural, electronic and thermoelectric properties of Sb2Se3 have been studied by using FP-LAPW method combined with Boltzmann transport theory. The variation of lattice constants, band structure, density of states, seebeck coefficient, electrical conductivity, electronic part of thermal conductivity and figure of merit (ZT) with pressure (up to 45.2 GPa) are calculated. Our results show that Sb2Se3 has a direct band gap of 1.43 eV in the bulk structure and it has an indirect band gap of 0.4 eV in the monolayer structure, at zero pressure. Increasing pressure led to a decrease in the band gap value and the nature of the band gap shifts from direct to the indirect. With the increase in pressure, the seebeck coefficient, electrical conductivity and electronic part of thermal conductivity increase and ZT decreases. The maximum ZT of 1.12 was achieved at 800 K, n = 1019 per cm−3 for n -type doping. Hence, Sb2Se3 is a good candidate for thermoelectric applications. The obtained results are in close agreement with the experimental results.