Graphene/Copper Nanoparticles as Thermal Interface Materials
Pengju Sun, Bowen Liu, Ziyun You, Yanmei Zheng, Zhaoshou Wang
Abstract
Recently, graphene was extensively applied in the fields of electronic and thermal management for its extraordinary thermal conductivity (TC). The graphene prepared by venturi-assisted supercritical CO2 (scCO2) exfoliation has lots of advantages such as high quality, few defects, and extremely high in-plane TC and is usually used as thermal interface material (TIM). However, it was difficult to meet the development of three-dimensional integration due to the thermal anisotropy. Herein, we successfully introduced copper nanoparticles into graphene sheets to prepare the graphene nanocopper (Gr/Cu) composites with highly aligned graphene nanoplatelet by a vacuum filtration method. The unique structure of copper nanoparticles can significantly weaken the thermal anisotropy by providing a heat transfer channel for the graphene nanoplatelet. Experimental results revealed that through-plane thermal conductivity of Gr/Cu composites was increased by 2.05 times (5.22 W m–1 K–1) with 20 wt % copper nanoparticles doping and the thermal anisotropy decreased from 247 to 45, which means that there is great potential for TIMs.