title: High on/off ratios in bilayer graphene field effect transistors realized by surface dopants.
abstract: The unique property of bilayer graphene to show a band gap tunable by external electrical fields enables a variety of different device concepts with novel functionalities for electronic, optoelectronic, and sensor applications. So far the operation of bilayer graphene-based field effect transistors requires two individual gates to vary the channel's conductance and to create a band gap. In this paper, we report on a method to increase the on/off ratio in single gated bilayer graphene field effect transistors by adsorbate doping. The adsorbate dopants on the upper side of the graphene establish a displacement field perpendicular to the graphene surface breaking the inversion symmetry of the two graphene layers. Low-temperature measurements indicate that the increased on/off ratio is caused by the opening of a mobility gap.
authors.affiliation: Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Strasse 25, 52074 Aachen, Germany. szafranek@amo.de
authors.forename: B N
authors.initials: BN
authors.lastname: Szafranek
authors.forename: D
authors.initials: D
authors.lastname: Schall
authors.forename: M
authors.initials: M
authors.lastname: Otto
authors.forename: D
authors.initials: D
authors.lastname: Neumaier
authors.forename: H
authors.initials: H
authors.lastname: Kurz
mesh_terms: D000327:Adsorption; D006108:Graphite / Q000737:chemistry*; D036103:Nanotechnology; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014173:Transistors, Electronic
chemical_list: D012822:Silicon Dioxide; D006108:Graphite