Field Emission from Carbon Systems

ABSTRACTElectron field emission from diamond, diamond-like carbon, carbon nanotubes and nanostructured carbon is compared. It is found that in all practical cases that emission occurs from regions of positive electron affinity with a barrier of ∼5 eV and with considerable field enhancement. The field enhancement in nanotubes arises from their geometry. In diamond, the field enhancement occurs by depletion of grain boundary states. In diamond-like carbon we propose that it occurs by the presence of sp2-rich channels formed by the soft conditioning process.