Thermal transport in MoS₂/Graphene hybrid nanosheets

Heat dissipation is a very critical problem for designing nano-functional devices, including MoS₂/graphene heterojunctions. In this paper we investigate thermal transport in MoS₂/graphene hybrid nanosheets under various heating conditions, by using molecular dynamics simulation. Diverse transport processes and characteristics, depending on the conducting layers, are found in these structures. The thermal conductivities can be tuned by interlayer coupling, environment temperature, and interlayer overlap. The highest thermal conductivity at room temperature is achieved as more than 5 times of that of single-layer MoS₂ when both layers are heated and 100% overlapped. Different transport mechanisms in the hybrid nanosheets are explained by phonon density of states, temperature distribution, and interlayer thermal resistance. Our results could not only provide clues to master the heat transport in functional devices based on MoS₂/graphene heterojunctions, but are also useful for analyzing thermal transport in other van der Waals hybrid nanosheets. (paper)