title: Metal-graphene-metal sandwich contacts for enhanced interface bonding and work function control.
abstract: Only a small fraction of all available metals has been used as electrode materials for carbon-based devices due to metal-graphene interface debonding problems. We report an enhancement of the bonding energy of weakly interacting metals by using a metal-graphene-metal sandwich geometry, without sacrificing the intrinsic π-electron dispersions of graphene that is usually undermined by strong metal-graphene interface hybridization. This sandwich structure further makes it possible to effectively tune the doping of graphene with an appropriate selection of metals. Density functional theory calculations reveal that the strengthening of the interface interaction is ascribed to an enhancement of interface dipole-dipole interactions. Raman scattering studies of metal-graphene-copper sandwiches are used to validate the theoretically predicted tuning of graphene doping through sandwich structures.
authors.affiliation: Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Gong
authors.forename: David
authors.initials: D
authors.lastname: Hinojos
authors.forename: Weichao
authors.initials: W
authors.lastname: Wang
authors.forename: Nour
authors.initials: N
authors.lastname: Nijem
authors.forename: Bin
authors.initials: B
authors.lastname: Shan
authors.forename: Robert M
authors.initials: RM
authors.lastname: Wallace
authors.forename: Kyeongjae
authors.initials: K
authors.lastname: Cho
authors.forename: Yves J
authors.initials: YJ
authors.lastname: Chabal
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical
chemical_list: D008670:Metals; D006108:Graphite