Ferroelectrically driven spatial carrier density modulation in graphene.
- Author(s): Baeumer, Christoph;
- Saldana-Greco, Diomedes;
- Martirez, John Mark P;
- Rappe, Andrew M;
- Shim, Moonsub;
- Martin, Lane W
- et al.
Published Web Locationhttps://doi.org/10.1038/ncomms7136
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.