Band dependent field electron emission from the graphene

Summary form only given. Graphene has a one-dimensional edge of atomic thickness, excellent electrical conductivity, and good mechanical properties, which qualify it as an attractive novel field emission emitter. Several groups had demonstrated that graphene does show promising electron emission properties, such as low emission threshold field and large emission current density[1-7]. The traditional Fowlor-Nordheim (FN) theory is suitable for planar emitter only. There had been many theory studies of field emission from carbon nanotubes, that are based on quantum chemistry calculation[8-19] and classical electromagnetism[8, 20-23]. The floating sphere model successfully provided an analytic expression for the potential barrier near the apex of carbon nanotube[24]. S. Watcharotone et al. obtained the field enhancement factor on the corners and edges of graphite sheets numerically by employing the boundary element method[25]. In the present study, we propose a floating sheet model for analytic expression of potential barrier of graphene. The field electron emission current from the armchair edge of the graphene is studied analytically. The unique electronic structure of the graphene and the field penetration in the edge have been taken into account. The calculated slope of the Fowler-Nordheim plot of field emission is in consistent with those measured in experiments[l, 3, 5, 6, 26].