The importance of van der Waals interactions to thermal transport in Graphene-C60 heterostructures

Graphene-C60 heterostructures assembled by van der Waals (vdW) interactions between graphene and C60 have shown exciting potential for multifunctional devices. Understanding thermal transport in graphene-C60 heterostructures is the key to guiding the design of vdW heterostructures with desired thermal transport properties. In this work, we report the first study of thermal transport in a graphene-C60 heterostructure and elucidate the importance of vdW interactions to heat conduction using molecular dynamics simulations. We find that the in-plane thermal conductivity of the graphene-C60 heterostructure is as high as about 234 W/(mK) at room temperature, exceeding those of most pure metals. As the vdW interaction parameter, χ, varies from 0.1 to 2, the in-plane thermal conductivity first increases then decreases. On the other hand, as vdW interactions increases, the interfacial thermal conductance between graphene and C60 is enhanced. Our study demonstrates that graphene-C60 heterostructures have high in-plane thermal conductivity and their interfacial thermal conductance is comparable to that of graphene-hexagonal boron-nitride (hBN) heterostructure. Graphene-C60 heterostructures are promising candidates for multifunctional devices with inherent heat dissipation capability.