Theoretical study of Cr 2 X 3 S 3 (X = Br, I) monolayers for thermoelectric and spin caloritronics properties.

High curie temperature 2D materials are important for the progress of the field of spin caloritronics. The spin Seebeck effect and conventional thermoelectric figure of merit (ZT) can give a great insight into how these 2D magnetic materials will perform in spin caloritronics applications. Here in this paper, we have systematically studied 2D Janus monolayers based on CrX 3 monolayers. We obtain a ZT of 0.31 and 0.21 for the Cr 2 Br 3 S 3 and Cr 2 I 3 S 3 Janus monolayers. The spin Seebeck coefficient obtained at room temperature is also very high (∼1570 μ VK -1 in the hole-doped region and ∼1590 μ VK -1 in the electron-doped region). The thermal conductivity of these monolayers (∼22 Wm -1 K -1 for Cr 2 Br 3 S 3 and ∼16 Wm -1 K -1 for Cr 2 I 3 S 3 ) are also very similar to other 2D semiconductor transition metals chalcogenides. These findings suggest a high potential for these monolayers in the spin caloritronics field.