title: Atomistic boron-doped graphene field-effect transistors: a route toward unipolar characteristics.
abstract: We report fully quantum simulations of realistic models of boron-doped graphene-based field-effect transistors, including atomistic details based on DFT calculations. We show that the self-consistent solution of the three-dimensional (3D) Poisson and Schrödinger equations with a representation in terms of a tight-binding Hamiltonian manages to accurately reproduce the DFT results for an isolated boron-doped graphene nanoribbon. Using a 3D Poisson/Schrödinger solver within the non-equilibrium Green's function (NEGF) formalism, self-consistent calculations of the gate-screened scattering potentials induced by the boron impurities have been performed, allowing the theoretical exploration of the tunability of transistor characteristics. The boron-doped graphene transistors are found to approach unipolar behavior as the boron concentration is increased and, by tuning the density of chemical dopants, the electron-hole transport asymmetry can be finely adjusted. Correspondingly, the onset of a mobility gap in the device is observed. Although the computed asymmetries are not sufficient to warrant proper device operation, our results represent an initial step in the direction of improved transfer characteristics and, in particular, the developed simulation strategy is a powerful new tool for modeling doped graphene nanostructures.
authors.affiliation: Dipartimento di Ingegneria dell'Informazione, Università di Pisa, Via Caruso 16, 56122 Pisa, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Marconcini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cresti
authors.forename: François
authors.initials: F
authors.lastname: Triozon
authors.forename: Gianluca
authors.initials: G
authors.lastname: Fiori
authors.forename: Blanca
authors.initials: B
authors.lastname: Biel
authors.forename: Yann-Michel
authors.initials: YM
authors.lastname: Niquet
authors.forename: Massimo
authors.initials: M
authors.lastname: Macucci
authors.forename: Stephan
authors.initials: S
authors.lastname: Roche
mesh_terms: D001895:Boron / Q000737:chemistry*; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D014173:Transistors, Electronic
chemical_list: D006108:Graphite; D001895:Boron