Planar Graphene Edge Field Emitter Design with Improved Emission Current

Abstract

We demonstrate field emission from planar graphene edges fabricated using a new method. The device uses narrow cantilevered metal beams to support the graphene. To date we have measured emission currents over 10μA from edges less than 50μm long, three orders of magnitude improvement over previous results. Millikan-Lauritsen plots result in straight lines. The electron energy spectra demonstrate field emission but are sometimes broadened on the low energy side relative to standard field emission theory, suggesting the Fermi energy was shifted by up to several eV along the edge. The cause of the shift may be adsorbed fluorine atoms which reduce the electron density in graphene.