Mechanisms of field emission from diamond coated Mo emitters

A combination of field emission energy distribution (FEED) and I-V measurements was used to study the field emission mechanisms of tip-shaped molybdenum emitters electrophoretically coated with nominally intrinsic diamond powders. Field-induced band bending was studied as a function of applied voltage and was interpreted in terms of a two-barrier model. Field emitted electrons originated from the conduction band minimum of diamond. Electron injection at the Mo/diamond interface was identified as the dominant field emission current limiting factor. It was concluded that potential negative electron affinity (NEA) properties of diamond did not contribute to a current enhancement. The latter statement was confirmed by the observation that graphite coatings enhanced emission currents in a similar way to diamond coatings. (C) 1998 Elsevier Science S.A.