Surface characterization and electrical properties of spin- coated graphene conductive film

The Excellent printability of graphene sheets on large scale, flexible substrates makes graphene a perfect substitute of traditional conductive material in electronics industry. In this letter we demonstrate several properties of conductive film prepared by spin-coating graphene on PET substrates. After spin coating and air dry, the graphene film had a sheet resistance of 47.4Ω/□, resistivity of 1.07 mΩ·m. With a subsequent heating at 70°C, the resistivity was reduced to 0.18mΩ·m due to more outgassed liquidous solution and better contact of graphene nanoplatelet. Multilayer films were also prepared, and the graphene resistivity and microstructure versus film thickness was investigated. It is observed that the electric resistance declines as the film thickness increases. The thick film resulted in less-rough surface according to Scanning Electronic Microscope (SEM) and Atomic Force Microscope (AFM) inspection.