Bulk and monolayer As2S3 as promising thermoelectric material with high conversion performance
Abhishek Patel, Deobrat Singh, Yogesh Sonvane, P. B. Thakor, Rajeev Ahuja
Abstract
The electronic and thermoelectric properties of recently synthesized As2S3 in the form of 2D by experiment have been investigated in this work. The thermoelectric properties of As2S3 has been studied by the first-principles calculations and the Boltzmann Transport theory. The result shows that As2S3 has indirect band gap of 2.31 eV for monolayer and 2.08 eV for bulk. From phonon 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 As2S3 and 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 As2S3 while in case of monolayer As2S3, the values of S have less variation with increasing temperature. The electronic figure of merit (ZTe) for bulk As2S3 is found to be 5.04 at 300 K while at higher temperature ZTe values significantly reduced to 3.76. For monolayer As2S3, the electronic figure of merit, ZTe is also showed higher value of 1.84 at 300 K and at higher temperature it has ~ 2.75. These investigation shows that the bulk and monolayer have new materials for the potential applications in the thermoelectric devices.