Bulk and monolayer As2S3 as promising thermoelectric material with high conversion performance

[Display omitted] •Thermoelectric properties of bulk and monolayer of As2S3.•Structural, Electronic, and phonon dispersion calculations.•As2S3 shows indirect band gap 2.31 eV for monolayer and 2.08 eV for bulk.•Seebeck coefficient are 188 and 298 mV/K for monolayer and bulk at 300 K.•ZTe value of bulk As2S3 is 5.04 and 2.75 for monolayer at room temperature. Theelectronic and thermoelectric properties of recently synthesized As2S3in the form of2Dby experiment have been investigated in this work. The thermoelectric properties of As2S3has been studied by the first-principles calculations and the Boltzmann Transport theory. The result shows that As2S3has indirect band gap of 2.31 eV for monolayer and 2.08 eV for bulk. Fromphonon dispersion spectra, both bulk and monolayer have dynamical stability. The Seebeck coefficient (S) as a function of temperature is investigated for monolayer and bulk of As2S3and its values at 300 K temperature are 188 and 298 μV/K. Also, the values of S are drastically decreasing when temperature increases in bulk As2S3while in case of monolayer As2S3,the values of S have less variation with increasing temperature. The electronic figure of merit (ZTe) for bulk As2S3is found to be 5.04 at 300 K while at higher temperature ZTevalues significantly reduced to 3.76. For monolayer As2S3, the electronic figure of merit, ZTeis also showed higher value of 1.84 at 300 K and at higher temperature it has ~ 2.75. These investigation shows that the bulk andmonolayer have new materials for the potential applications in the thermoelectric devices.