Resonant orbitals in fluorinated epitaxial graphene

Fluorinated epitaxial graphene has potential applications in organic electronics. We present the calculation results by means of first-principles density-functional-theory for various fluorination patterns. Our results indicate that semi-fluorinated graphene conformations follow the same energetic order as the corresponding hydrogenated graphene counterparts. The distinctive electronic properties between semi-hydrogenated graphene and semi-fluorinated graphene are attributed to the polar covalent C-F bond in contrast to the covalent C-H bond. The partial ionic character of the C-F bond results in the hyperconjugation of C-F σ-bonds with an sp 2 network of graphene. Resonant orbitals stabilize the stirrup conformation via the gauche effect. Resonant orbitals also lead to electron doping of the sp 2 network and enhanced excitonic effect. The implications of resonant-orbital-induced doping for the electronic and magnetic properties of fluorinated epitaxial graphene are discussed. Fluorinated epitaxial graphene has potential applications in organic electronics.