The role of tunneling barrier modification for the saturation current of carbon nanotube field emission in strong electric field

► We describe a model for non-Fowler-Nordheim behavior in field emission from carbon nanotubes. At very high electric fields the tunneling barrier converts to a constant potential barrier. Field emission current density saturates due to a constant barrier formation. We find that the saturation in current density occurs at an applied field of ⩾3×106 V/m. This corresponds to a local electric field of ⩾3×109 V/m on the tip.