Characteristic performances of carbon nanotube field emission cathode

The field emission behaviors of multi-walled carbon nanotubes (CNTs) electron source are investigated. The CNT emitters were grown directly on the Ni alloy substrate by the chemical vapor deposition. Anode current 41 μA under 310 V gate voltage with the electron transmission rate of about 70-75%, only about 10% lower than the gate transparency. The electric field generated from the anode could penetrate through the gate grid to enhances the field emission by 30-50 %. There could be a serious pressure rise in the operation due to mainly the molecule desorption from the metal electrodes (gate and anode) by the electron bombardment.