Doping graphene with metal contacts

Abstract

Making devices with graphene necessarily involves making contacts with metals. We use density functional theory to study how graphene is doped by adsorption on metal substrates and find that weak bonding on Al, Ag, Cu, Au and Pt, while preserving its unique electronic structure, can still shift the Fermi level with respect to the conical point by $\sim 0.5$ eV. At equilibrium separations, the crossover from $p$-type to $n$-type doping occurs for a metal work function of $\sim 5.4$ eV, a value much larger than the graphene work function of 4.5 eV. The numerical results for the Fermi level shift in graphene are described very well by a simple analytical model which characterizes the metal solely in terms of its work function, greatly extending their applicability.

4 pages, 5 figures

References in corpus (10)

• Electric Field Effect in Atomically Thin Carbon Films
• Chiral tunneling and the Klein paradox in graphene
• Unconventional Integer Quantum Hall effect in graphene
• Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
• Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
• Two Dimensional Ir-Cluster Lattices on Moiré of Graphene with Ir(111)
• Graphite and graphene as perfect spin filters
• Tailoring Graphene with Metals on Top
• Effective contact model for transport through weakly-doped graphene
• Transport through normal metal - graphene contacts

Cited by in corpus (13)

• Dirac Cones and Minigaps for Graphene on Ir(111)
• Evidence of the role of contacts on the observed electron-hole asymmetry in graphene
• Atomic Hole Doping of Graphene
• Tuning the electronic structure of graphene by ion irradiation
• Theoretical prediction of perfect spin filtering at interfaces between close-packed surfaces of Ni or Co and graphite or graphene
• A tight-binding potential for atomistic simulations of carbon interacting with transition metals: Application to the Ni-C system
• Contact resistance and shot noise in graphene transistors
• Effective medium theory for disordered two-dimensional graphene
• Energy gap opening in submonolayer lithium on graphene: Local density functional and tight-binding calculations
• Quantum resistance metrology in graphene
• Transfer Characteristics in Graphene Field-Effect Transistors with Co Contacts
• Disorder-induced pseudodiffusive transport in graphene nanoribbons
• Quantum Hall conductance of two-terminal graphene devices