Optoelectronic and thermoelectric properties of Sb2S3 under hydrostatic pressure for energy conversion

This study reports the optoelectronic and thermoelectric properties of antimony trisulfide (Sb2S3) under a hydrostatic pressure of up to 20.4 GPa. The properties were computed based on the full-potential linearized augmented plane wave using the generalized gradient approximation by Perdew, Burke, and Ernzerhof as the exchange-correlation potentials. It was shown that increasing the pressure from 0.00 to 20.4 GPa decreases the calculated bandgap from 1.44 to 0.84 eV. There was a discontinuity in the pressure range of 4.82–6.3 GPa due to the isostructural electronic phase transition. The applied pressure increases the inner electrical polarization. At high pressure, the energy of the negative value of ε1 becomes large, and ε1 itself always remains negative. We observed that the high absorption of Sb2S3 also increases with pressure and the plasmon energy shifts to high energy. The applied pressure increases the static dielectric constant and static refractive index. It was found that the Seebeck coefficients increase with increasing temperature and decrease with increasing pressure. The bipolar effect occurs at low doping levels and high pressure. The optical and thermoelectric properties of Sb2S3 obtained under pressure show that it is suitable for clean energy conversion and optoelectronic applications.