ENHANCEMENT OF GRAPHENE BINDING ENERGY BY Ti 1ML INTERCALATION BETWEEN GRAPHENE AND METAL SURFACES

We theoretically investigate the effects of intercalation of a thin Ti layer between graphene (Gr) and metal surface (Au, Ag, Al, Pt, and Pd) on structural and electronic properties by using the first-principles total energy calculations. We find that the strongest binding energy is realized when 1 monolayer (ML) of Ti is intercalated between Gr and a metal surface independent of the metal atoms, which is 0.08-0.15 eV larger than that for Gr absorbed on a Ti(0001) surface. As the number of Ti layers increases, the binding energy monotonically decreases and converges to that for Gr adsorbed onto the Ti surface. We show that the origin of the enhancement of binding energy can be classified into two classes by considering the affinity of Ti for the metal surfaces.