ABSTRACT
Field emission (FE) (also known as eld electron emission or electron eld emission) is the emission of electrons from a solid surface into vacuum induced by an electrostatic eld. FE was rst explained by quantum tunneling of electrons in the late 1920s [1], and the theory of FE from bulk metals was proposed by Fowler and Nordheim [2]. A family of approximate equations, called Fowler-Nordheim equations (F-N equations), are named in their honor and have been shown in terms of experimentally measured quantities as
ln offset I
V V d
3 21
=
+
aj b
(8.1)
where φ is the work function (WF) of the emitter, d is the interelectrode distance, β is the eld amplication factor (eld enhancement factor) determined by the geometry of the emission region, and α is a constant [3]. The hypothesis of this model includes
1. Electrons are fermions, and their distribution meets Fermi-Dirac statistics. 2. The surface of the metal is a smooth plane, and its atomic-scale irregularities can be
ignored. 3. The inuence of the classic mirror-image force is taken into consideration. 4. The distribution of work functions is uniform.
