title: Chemical doping and electron-hole conduction asymmetry in graphene devices.
abstract: We investigate poly(ethylene imine) and diazonium salts as stable, complementary dopants on graphene. Transport in graphene devices doped with these molecules exhibits asymmetry in electron and hole conductance. The conductance of one carrier is preserved, while the conductance of the other carrier decreases. Simulations based on nonequilibrium Green's function formalism suggest that the origin of this asymmetry is imbalanced carrier injection from the graphene electrodes caused by misalignment of the electrode and channel neutrality points.
authors.affiliation: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: Damon B
authors.initials: DB
authors.lastname: Farmer
authors.forename: Roksana
authors.initials: R
authors.lastname: Golizadeh-Mojarad
authors.forename: Vasili
authors.initials: V
authors.lastname: Perebeinos
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Lin
authors.forename: George S
authors.initials: GS
authors.lastname: Tulevski
authors.forename: James C
authors.initials: JC
authors.lastname: Tsang
authors.forename: Phaedon
authors.initials: P
authors.lastname: Avouris
mesh_terms: D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004579:Electron Transport; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006108:Graphite