Electron field emission from nanostructured diamond and carbon nanotubes

Both diamond and carbon nanotubes are efficient field emitters because of the negative electron affinity associated with the diamond surface and the geometrically nanometer-scale nature of the nanotubes. They offer the important advantage of ease in fabrication and low-cost manufacturing. Both materials have been shown to emit electrons at very low electric fields (3-7 V/mum for a current density of 10 mA/cm(2)). Moreover, nanotube emitters are found to be able to deliver very high emission currents densities, with current density routinely exceeding 1 A/cm(2). The low field operation of these carbon based emitters is attractive for display applications, while the high current capability of nanotube emitters will enable a number of high power, high frequency devices. Further improvements over the emission uniformity hold the key for the realization of the potential of these carbon materials in enabling practically useful cold cathode devices. (C) 2001 Elsevier Science Ltd. All rights reserved.