Viable thermionic emission from graphene-covered metals

Abstract

Thermionic emission from monolayer graphene grown on representative transition metals, Ir and Ru, is characterized by low-energy electron microscopy (LEEM). Work functions were determined from the temperature dependence of the emission current and from the electron energy spectrum of emitted electrons. The high-temperature work function of the strongly interacting system graphene/Ru(0001) is sufficiently low, 3.3 \pm 0.1 eV, to have technological potential for large-area emitters that are spatially uniform, efficient, and chemically inert. The thermionic work functions of the less strongly interacting system graphene/Ir(111) are over 1 eV larger and vary substantially (0.4 eV) between graphene orientations rotated by 30°.

Published in Applied Physics Letters

References in corpus (9)

• First-principles study of the interaction and charge transfer between graphene and metals
• Two Dimensional Ir-Cluster Lattices on Moiré of Graphene with Ir(111)
• Dirac Cones and Minigaps for Graphene on Ir(111)
• Factors influencing graphene growth on metal surfaces
• Defects of graphene on Ir(111): rotational domains and ridges
• In-plane orientation effects on the electronic structure, stability and Raman scattering of monolayer graphene on Ir(111)
• A possible source of spin-polarized electrons: The inert graphene/Ni(111) system
• Kinetics and thermodynamics of carbon segregation and graphene growth on Ru(0001)
• Oxidation of graphene on metals

Cited by in corpus (5)

• Electron Thermionic Emission from Graphene and a Thermionic Energy Converter
• Graphene growth and properties on metal substrates
• Generalized high-energy thermionic electron injection at graphene interface
• Scanning probe microscopy and spectroscopy of graphene on metals
• Multichannel scanning probe microscopy and spectroscopy of graphene moire structures