title: Transfer characteristics and contact resistance in Ni- and Ti-contacted graphene-based field-effect transistors.
abstract: We produced graphene-based field-effect transistors by contacting mono- and bi-layer graphene by sputtering Ni or Ti as metal electrodes. We performed electrical characterization of the devices by measuring their transfer and output characteristics. We clearly observed the presence of a double-dip feature in the conductance curve for Ni-contacted transistors, and we explain it in terms of charge transfer and graphene doping under the metal contacts. We also studied the contact resistance between the graphene and the metal electrodes with larger values of ~30 kΩμm(2) recorded for Ti contacts. Importantly, we prove that the contact resistance is modulated by the back-gate voltage.
authors.affiliation: Dipartimento di Fisica E R Caianiello and Centro Interdipartimentale NANO_MATES, Università degli Studi di Salerno, via Ponte don Melillo, I-84084, Fisciano (Sa), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Di Bartolomeo
authors.forename: F
authors.initials: F
authors.lastname: Giubileo
authors.forename: L
authors.initials: L
authors.lastname: Iemmo
authors.forename: F
authors.initials: F
authors.lastname: Romeo
authors.forename: S
authors.initials: S
authors.lastname: Santandrea
authors.forename: U
authors.initials: U
authors.lastname: Gambardella