High Thermoelectric Performance in Two-Dimensional Janus Monolayer Material WS-X (X = Se and Te)

Abstract

In the present work, Janus monolayers WSSe and WSTe are investigated by combining first-principles calculations and semiclassical Boltzmann transport theory. Janus WSSe and WSTe monolayers show a direct band gap of 1.72 and 1.84 eV at K-points, respectively. These layered materials have an extraordinary Seebeck coefficient and electrical conductivity. This combination of high Seebeck coefficient and high electrical conductivity leads to a significantly large power factor. In addition, the lattice thermal conductivity in the Janus monolayer is found to be relatively very low as compared to the WS 2 monolayer. This leads to a high figure of merit (ZT) value of 2.56 at higher temperatures for the Janus WSTe monolayer. We propose that the Janus WSTe monolayer could be used as a potential thermoelectric material due to its high thermoelectric performance. The result suggests that the Janus monolayer is a better candidate for excellent thermoelectric conversion.

Mechanical, optical, and thermoelectric properties of semiconducting ZnIn2X4 (X= S, Se, Te) monolayers

“…The highest thermopower reported for Sn 2 Bi is 300 µV/K [54] while it is 500 µV/K for the Pd 2 Se 3 monolayer [55]. Also, the thermopower of WS 2 and WSTe monolayers are 328 and 322 µV/K [56], much lower than our results.…”

Low-cost pentagonal NiX2 (X = S, Se, and Te) monolayers with strong anisotropy as potential thermoelectric materials

“…29,30 The extensively studied TMDCs with the out-of-plane structures exhibit high thermoelectric performance such as the hexagonal 2H-phase HfSSe with ultra-low lattice thermal conductivity ( ZT = ∼0.65 for n-type HfSSe with K l = ∼2.23 W mK −1 at 300 K) and the hexagonal 2H-phase WSTe with high thermoelectric performance ( ZT = ∼2.6 for n-type WSTe with K l = ∼0.025 W mK −1 at 1200 K). 31,32…”

Dimensionality effects in high‐performance thermoelectric materials: Computational and experimental progress in energy harvesting applications

“…32 Some other investigations also suggest that the LD materials improved the TE performance. 108,[156][157][158][159][160][161][162][163][164][165][166] The lists of novel LD TE materials for high TE performance are summarized in Table 2. From these results, the nanostructures significantly improved the performance of TE materials.…”