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Title: Field emission spectroscopy evidence for dual-barrier electron tunnelling in nanographite

Nanocarbon films with upstanding flake-like graphite crystallites of nanometre thickness were fabricated by carbon condensation from a methane–hydrogen gas mixture activated by a direct-current discharge. The nanographite (NG) crystallites are composed of a few graphene layers. The adjacent atomic layers are connected partially at the edges of the crystallites to form strongly curved graphene structures. The extraordinary field emission (FE) properties were revealed for the NG films with an average current density of a few mA/cm{sup 2}, reproducibly obtained at a macroscopic applied field of about 1 V/μm. The integral FE current–voltage curves and electron spectra (FEES) of NG cathodes with multiple emitters were measured in a triode configuration. Most remarkably, above a threshold field, two peaks were revealed in FEES with different field-dependent shifts to lower energies. This behaviour evidences electron emission through a dual potential barrier, corresponding to carbon–carbon heterostructure formed as a result of the graphene bending.
Authors:
;  [1] ; ; ;  [2] ;  [1] ;  [3]
  1. Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)
  2. FB C Physics Department, University of Wuppertal, 42119 Wuppertal (Germany)
  3. (Finland)
Publication Date:
OSTI Identifier:
22412568
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ELECTRIC CONDUCTIVITY; ELECTRON EMISSION; ELECTRON SPECTRA; ELECTRONS; FIELD EMISSION; FILMS; GRAPHENE; GRAPHITE; LAYERS; NANOSTRUCTURES; SPECTROSCOPY; TUNNEL EFFECT