Electron emission from the side wall of an individual multiwall carbon nanotube

Electron emission from the sidewall of a bent individual multiwall carbon nanotube (CNT) is reported. The CNT was synthesized using a catalytic chemical vapor deposition method and the focused-ion beam technique was used to fabricate the CNT-based electron emitter. With controlled ion bombardment, individual carbon nanotubes can be bent into loops with different radii. An external electric field can be used to straighten the bent CNT. The electron field emission from the sidewall of CNT was measured, and compared with that from the tip of the CNT. The turn-on voltage from the sidewall of CNT is significantly lower than that from the tip. An enhancement factor β as large as 400,000 has been obtained for the electron emission from the side wall.