Theoretical Design of Highly Efficient 2D Thermoelectric Device Based on Janus MoSSe and Graphene Heterostructure

Abstract

Two dimensional (2D) materials are emerging candidates for thermoelectric applications because of their exceptional electronic and mechanical properties. A serious impediment to improving thermoelectric (TE) efficiency is electrical (σ) and thermal (κ) conductivity, which are related and cannot be tuned separately. In this study, we have shown that the heterostructures of Janus MoSSe and graphene have a negative correlation between electrical and thermal conductivity. It is also possible to design both p-type and n-type legs by using a pure and phosphorus-doped heterostructure. We obtained a power factor of 3410 μW m–1 K–2 for p-type and 2450 μW m–1 K–2 for n-type cases at room temperature. The lattice thermal conductivity is reduced to 13.28 W m–1 K–1 for pure and 8.36 W m–1 K–1 for the P-doped heterostructure from 17.32 W m–1 K–1 for Janus MoSSe at 300 K. A promising figure of merit is obtained for the 2D TE device made by Janus MoSSe and graphene heterostructures.