Thermoelectric response of 1T-ZrS2 monolayer: Ab-initio study

Abstract

The development of highly efficient thermoelectric materials has greatly assisted by two-dimensional transition metal dichalcogenides. The present work deals with the study of structural, electronic, and thermoelectric properties of 1T-ZrS2 monolayer by employing ab-initio calculations in combination with Boltzmann transport equation. The performance of thermoelectric materials is represented by the value of the figure of merit (ZT). The electronic band structure of 1T-ZrS2 monolayer is confirmed its semiconducting nature with indirect band gap value of 1.20 eV. Phonon dispersion curve indicates the monolayer stability. Low lattice thermal conductivity is primarily caused by the strong interaction of low frequency acoustic modes with optical modes, which leads to a high ZT value for the suggested monolayer. The Seebeck coefficient, which is higher for n-type doping than p-type doping, indicates that n-type doping ZT value is more effectively optimised than p-type doping. At room temperature, a high value of ZT (=0.9) is attained, and its value varies with temperature. Based on the above study, 1T-ZrS2 monolayer may act as the potential candidates for its use as thermoelectric materials.