The Klein tunneling modified field emission model for a vertically-aligned single-layer graphene sheet

Summary form only given. Since the first single layer graphene is isolated in 2004, it rapidly becomes one of the hottest research areas in material physics. It is also proven to be an excellent field emission (FE) source with low turn on voltage, high emission current density, high emission stability and long lifetime. However, most of the experimental groups still treat graphene as a conventional field emitter and fit its field emission J-F characteristic with the classical Fowler-Nordheim (FN) law. Few have considered the effect of its unusual physical properties at the low energy level, eg. charity and Klein tunneling. In this paper, we are interested to develop a new model to include the effects of charity and linear energy dispersion for field emitted electron from a vertical-aligned single-layer graphene sheet. Our results will illustrate that the traditional FN law is no longer valid in the studied system. The emitted electron current line density (J [A/m]) has a linear relationship with the surface electric field on the graphene sheet. The energy distribution and angular dependence of the electron emission are calculated. At high current regime, space charge effects will become important.