Thermoelectric Properties of the Snx$_{2}$ (X = Se, Te) and Janus Snsete 1t-Monolayers: A Dft-D3 Study

Abstract

We have investigated the materials, in 1T phase for SnX$_{2}$ (X = Se, Te) and the Janus SnSeTe monolayers, through combined density functional theory calculations with Boltzmann transport equations, since 1T phase monolayers have lower (better) lattice thermal conductivity (figure of merit ZT) than the 2H phases. Our results showed that the SnSeTe Janus 1T-monolayer has an intermediate behavior between the SnSe$_2$ and SnTe$_2$ 1T-monolayers and that at 800 K the figure of merit ZT for the p-type SnSe$_2$ 1T-monolayer has a maximum value of 1.07, while it is 2.04 and 1.45 for SnTe$_2$ and SnSeTe Janus 1T-monolayers, respectively. Our results showed that the SnSeTe Janus 1T-monolayer has a behavior that competes with the SnSe$_2$ and SnTe$_2$ 1T-monolayers at 800 K for the p-type, while the figure of merit ZT (maximum value) is higher for the SnTe$_2$ monolayer (2.04) compared to the SnSeTe Janus (1.45) and SnSe$_2$ (1.07) monolayers.

Keywords: Thermoelectric material\sep DFT\sep Figure of merit\sep Janus monolayer