Exceptional thermal interface properties of a three-dimensional graphene foam

We have uncovered some unusual thermal interface properties of a three-dimensional, flexible and interconnected graphene foam (GF). The thermal interfacial resistance of GF at Si-Al interface is as low as 0.04 cm2K W−1, which is one order of magnitude lower than conventional thermal grease and thermal paste-based thermal interfacial material (TIM). The thermal contact resistance was found to dominate the overall interfacial resistance of GF-based TIM, in as much as the bulk thermal conductivity of GF is rather high. The contact pressure-dependent thermal interfacial resistance of GF exhibits an asymptotic behavior, which converges into a plateau value at an ultralow contact pressure (∼0.1 MPa). Significantly, the GF-based TIM has shown a superior performance to vertically aligned carbon nanotubes currently held as the gold standard (at least ∼75% improvement in thermal interfacial resistance at Si-Al interface), thus providing a strong candidate for the next generation of high-performance carbon-based TIM.