title: Ferroelectrically driven spatial carrier density modulation in graphene.
abstract: The next technological leap forward will be enabled by new materials and inventive means of manipulating them. Among the array of candidate materials, graphene has garnered much attention; however, due to the absence of a semiconducting gap, the realization of graphene-based devices often requires complex processing and design. Spatially controlled local potentials, for example, achieved through lithographically defined split-gate configurations, present a possible route to take advantage of this exciting two-dimensional material. Here we demonstrate carrier density modulation in graphene through coupling to an adjacent ferroelectric polarization to create spatially defined potential steps at 180°-domain walls rather than fabrication of local gate electrodes. Periodic arrays of p-i junctions are demonstrated in air (gate tunable to p-n junctions) and density functional theory reveals that the origin of the potential steps is a complex interplay between polarization, chemistry, and defect structures in the graphene/ferroelectric couple.
authors.affiliation: Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Christoph
authors.initials: C
authors.lastname: Baeumer
authors.affiliation: Department of Chemistry, The Makineni Theoretical Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Diomedes
authors.initials: D
authors.lastname: Saldana-Greco
authors.affiliation: Department of Chemistry, The Makineni Theoretical Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: John Mark P
authors.initials: JM
authors.lastname: Martirez
authors.affiliation: Department of Chemistry, The Makineni Theoretical Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Rappe
authors.affiliation: Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA.
authors.forename: Moonsub
authors.initials: M
authors.lastname: Shim
authors.affiliation: 1] Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801, USA [2] Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA [3] Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Lane W
authors.initials: LW
authors.lastname: Martin