Field Emission from Carbon Nanotubes

Abstract

Field emission (FE) is the emission of electrons from a solid surface into vacuum induced by an electrostatic field. Carbon nanotube (CNT) emitters that are too closely packed would cause a screening effect that causes a large decrease in the enhancement factor. The field enhancement factor of many CNT emitters measured experimentally was found to be smaller than that expected from the ratio of height to diameter of the tubes. The effects of various gas species on the electronic structures and resultant FE properties have also been studied both experimentally and theoretically. CNTs have very good electrical conductivity and high current durability. The excellent FE properties of CNTs, such as low-voltage operation, good stability, stable and high emission current, and large field enhancement factor, have opened new application fields in CNT-based devices. The emission from an individual CNT can constitute as a point emitter.