Field emission from nanotube bundle emitters at low fields

The fabrication of nanotube field emitters with an onset field as low as 0.8 V/mu m is described and the low-field electron emission mechanism is discussed. These emitters are made using nanotube cathode deposit with the addition of epoxy resin. The preferred orientation of nanotubes in nanotube bundles of the deposit is preserved. The nanotube tips are sharpened by exposing the nanotube bundle surface to a microwave oxygen plasma. The local-field enhancement factor is estimated to be 8000 by using the Fowler-Nordheim equation. The low onset field is attributed to the well-distributed, highly orientated sharp tips at the sample surface. (C) 1997 American Institute of Physics.