Fluorine adsorption on the graphene films: From metal to insulator

Electronic structures of fluorinated graphene are investigated by calculations using first-principle density functional theory (DFT). Our results suggest that the average charges on carbons reduce and the adsorption energies increase along with increasing coverages, this agrees with other theoretical/experimental works which show that F adsorption causes p-doping to the graphene. All of the stable configurations with different coverages have a band gap except for the case with one atom adsorption which is metallic. There is a magnetic moment when the number of F adatoms in a supercell on graphene sheet is odd. The magnetism comes from the distortion caused by the interaction between F atom and graphene, which was also manifested in the experimental works of Nair et al. (2012). The band gap range implies that fluorinated graphene, at certain coverage levels, might be useful for solar applications. (C) 2014 Elsevier B.V. All rights reserved.