Comparative investigation of the thermoelectric transport properties of Janus ZrS2Se and ZrS3 bilayers

Abstract Inspired by the recent experimentally realized few-layers of ZrS3, we investigate the thermoelectric properties of ZrS3 and Janus ZrS2Se bilayers by first-principles calculations. Our calculations display that the room-temperature lattice thermal conductivities of Janus ZrS2Se bilayer are 2.57 and 2.62 W/mK in the x and y directions, which results from its stronger anharmonic phonon scattering with the disordered vibrations along in-plane direction. Besides, a high p-type power factor is also predicted in Janus ZrS2Se bilayer because of the groove-like bands and orbital degeneracy on the top of valence bands. Combining a superior power factor with a low lattice thermal conductivity, the optimal ZT values are 2.21 and 1.43 at 300 K for p-type and n-type doped Janus ZrS2Se bilayer. These results indicate that Janus ZrS2Se bilayer is a promising low-temperature thermoelectric material.