Electronic transport across metal-graphene edge contact

The electronic transport across metal-graphene edge-contact structures is studied by first principles methods. Unusual double-dip transmission as a function of Fermi level is found for a Pd electrode over varying grapheme lengths. Interface metal-carbon hybridization is shown to introduce random distribution of π -orbital local density of states at different carbon sites leading to transmission suppression. For a Ti electrode, two dips are merged into one with a ∼0.2 eV transport gap opening. Our work sheds light on the origin of intrinsic contact resistance at metal-graphene edge contact. (paper)