title: In Situ Transmission Electron Microscopy Modulation of Transport in Graphene Nanoribbons.
abstract: In situ transmission electron microscopy (TEM) electronic transport measurements in nanoscale systems have been previously confined to two-electrode configurations. Here, we use the focused electron beam of a TEM to fabricate a three-electrode geometry from a continuous 2D material where the third electrode operates as side gate in a field-effect transistor configuration. Specifically, we demonstrate TEM nanosculpting of freestanding graphene sheets into graphene nanoribbons (GNRs) with proximal graphene side gates, together with in situ TEM transport measurements of the resulting GNRs, whose conductance is modulated by the side-gate potential. The TEM electron beam displaces carbon atoms from the graphene sheet, and its position is controlled with nanometer precision, allowing the fabrication of GNRs of desired width immediately prior to each transport measurement. We also model the corresponding electric field profile in this three-terminal geometry. The implementation of an in situ TEM three-terminal platform shown here further extends the use of a TEM for device characterization. This approach can be easily generalized for the investigation of other nanoscale systems (2D materials, nanowires, and single molecules) requiring the correlation of transport and atomic structure.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Julio A
authors.initials: JA
authors.lastname: Rodríguez-Manzo
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Zhengqing John
authors.initials: ZJ
authors.lastname: Qi
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Alexander
authors.initials: A
authors.lastname: Crook
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: A T Charlie
authors.initials: AT
authors.lastname: Johnson
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Marija
authors.initials: M
authors.lastname: Drndić
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D004566:Electrodes; D004583:Electrons; D006108:Graphite / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D037742:Nanotubes, Carbon; D017655:Silicon Compounds; D006108:Graphite; C032734:silicon nitride; D012825:Silicon
keywords: electronic transport; graphene nanoribbons; in situ TEM; modulation; side gate; two-dimensional materials