Vertical Graphene on Graphene Composite Film for Heat Dissipation and Electromagnetic Shielding

Graphene film has extensive applications in the electronic field inspite of the high cost. Mechanical exfoliation is a cost-effective method for producing graphene (GP), while weak interconnections between them negatively affect the film performance. To address this issue, GP dispersion with a small amount of graphene oxide (GO) addition was vacuum filtrated, dried, and pressed into a graphene oxide/graphene (GO/GP) film. Then, vertical graphene (VG) was grown in situ on the surface of the GO/GP film using inductively coupled plasma-enhanced chemical vapor deposition (ICP-PECVD) and subsequently graphitized to fabricate the RGO/GP/VG composite film. The test results showed that the RGO/GP/VG composite film had a remarkable thermal conductivity of 581.89 W m–1K–1, surpassing that of the graphitized RGO/GP film (376.65 W m–1K–1) by 54.5% with a total thickness of about 24 μm. At the same time, excellent electrical conductivity and electromagnetic shielding effectiveness were also obtained, reaching 1556.01 S cm–1 and 60.40 dB, respectively. The structural evolution of VG during the graphitization and its impact on the dual functionality of the GP film were investigated in detail. The improvement in performance of the RGO/GP/VG composite film revealed that the synergistic effect of in situ grown VG and graphitization yielded more coherent thermal and electrical pathways.