Use of graphene-based films for hot spot cooling

Efficient heat dissipation is becoming an urgent demand in electronics and optoelectronics because of increasing power density, which is generating more heat than ever. Graphene, an atomic layer of carbon, has been shown to have high thermal conductivity, which makes this material a promising candidate for heat dissipation in electronics. Here, we demonstrate a new type of graphene-based film on a test platform to alleviate the thermal issues. Taking advantage of its high in-plane thermal conductivity, CVD-grown graphene has been observed to possess a strong heat-spreading ability. In this paper, a chemical conversion process, including chemical oxidation, exfoliation and reduction, is utilised to fabricate the graphene-based films. Additionally, functionalisation of the film was also performed to diminish the interface thermal resistance between the chip surface and the graphene-based films. Thermal characterisation showed a capacity for effective heat removal, which was indicated by the decrease in the hot spot temperature at the same power loading. In summary, this facile approach may technologically enable large-scale fabrication of graphene-based films for thermal management in high power density devices.