Annealing-induced one order of magnitude enhancement in heat dissipation at graphene/SiO2 interface

Abstract

The potential applications of two-dimensional (2D) materials-based devices in various fields have garnered significant interest. However, the limited heat transfer efficiency across the interface between 2D materials and the substrate has impeded their widespread application. This study presents a novel approach to enhancing the interface thermal transport of a widely used graphene/substrate structure through repeated annealing. Using Raman thermometry, we measured the interface thermal resistance (R) at 9.51 × 10−5 m2 K/W, which was subsequently reduced by an order of magnitude to 5.00 × 10−6 m2 K/W after repeated annealing. Our experimental results, supported by atomic modeling, revealed the significant influence of wrinkles on the interface thermal transport. Atomic force microscopy (AFM) images vividly illustrate the modulation of the surface structure due to repeated annealing, with the initial loose structure becoming tighter and the wrinkle flattened. Further phonon transport analysis revealed a significantly reduced phonon coupling rate between graphene and SiO2 due to the presence of wrinkles in the graphene. Our findings highlight the feasibility of annealing as a means of manipulating interface thermal transport and provide insights into the underlying mechanism, which may inspire further studies on enhancing thermal interface properties.