Electrical Control of the Chemical Bonding of Fluorine on Graphene

Original · EN

We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp³-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10¹4 cm-2) its electronic structure corresponds to a nearly pure sp² configuration. We interpret this sp³-sp² doping-induced crossover in terms of a simple tight binding model and discuss the physical consequences of this change.