Hybrid Graphene/Fluoropolymer Field-Effect Transistors With Improved Device Performance

We demonstrate high-performance field-effect transistors consisting of hybrid graphene/fluoropolymer films by investigating the molecular interaction with strong carbon-fluorine dipoles and hydrophobic surface characteristics. A simple and reproducible solution-coating method on a chemical vapor deposition grown monolayer graphene was employed with fluoropolymer, amorphous CYTOP, and polycrystalline poly(vinylidene fluoride-co-trifluoroethylene) as an interacting layer. All of the key device metrics, including field-effect mobility, Dirac voltage, residual carrier concentration, ON-OFF current ratio, and electron-hole transport symmetry, were substantially improved. Significantly, the Dirac voltage shifted in both directions toward zero, regardless of its initial positions of the Dirac voltage after molecular encapsulation with fluoropolymers. We also demonstrate the improved stability of hybrid graphene/fluoropolymer films that possesses a hydrophobic surface through repelling hydroxyl (-OH) functional groups from the graphene surface.