Electron field emission from carbon nanotubes: Modeling and simulations

Here, we present theoretical investigations on field emission properties of open and closed single-walled carbon nanotubes. These investigations include studies on the effects of geometry and electronic structure of the nanotubes. The electric field intensity and its spatial variation near the tips of open and closed nanotubes are calculated. The field intensity of an open nanotube in very close proximity of the tip is found to be higher but it decreases more rapidly with the distance. It is found that calculated emission currents from closed nanotubes are higher than that of open nanotubes at low electric fields. Emissions patterns are simulated and they are found to be related to the local electronic structure of the nanotube caps.