Investigation for Thermoelectric Properties of the MoS2 Monolayer- Graphene Heterostructure: Density Functional Theory Calculations and Electrical Transport Measurements

Abstract

We investigated the thermoelectric (TE) properties of the MoS2 monolayer-graphene heterostructure which consists of the MoS2 monolayer and graphene. The electronic structures of the MoS2 monolayer-graphene heterostructure are mainly contributed from graphene and the MoS2 monolayer for the valence band maximum and conduction band minimum, respectively. The change in the electronic structures near the Fermi level is responsible for the fact that the calculated Seebeck coefficients S and electrical conductivity sigma/tau of MoS2 monolayer-graphene are largely affected from those of graphene and the MoS2 monolayer. Its power factor S-2 sigma/tau is increased compared to those of graphene and the MoS2 monolayer at an electron concentration of 10(11) to 10(12) cm(-2), which corresponds to a three-dimensional concentration of 3 X 10(18) to 3 X 10(19) cm(-3). We also demonstrated that the MoS2 monolayer shows the p-type TE behavior, while the MoS2 monolayer-graphene heterostructure is given to the n-type TE material. The current study provides a strategy to improve TE properties of the MoS2 monolayer through the formation of the MoS2 monolayer-graphene heterostructure.