We consider a field emitter on the base of carbon nanotube film consisting from randomly wreathed tubes. Under applied voltage some long ends of nanotubes laying on a surface of film should be straightened by electrostatic forces and be oriented along force lines perpendicularly to the substrate. These nanotubes can hold in places due to several van der Waals contacts with other nanotubes of film and a contact with the substrate. In this work we present an exact solution for the electrostatic field between an elongated nanotube screening by other tubes on a plate and a flat anode. We calculate field enhancement factor on surface of a nanotube and electrostatic force acting on a tube. Using Fowler-Nordheim theory we derive exact analytical formula for total current from individual nanotube. Distributions of the field enhancement factor, total force and emission current on the top of nanotube for a wide range of parameters have been found and analyzed. The thermal field of nanotube and its influence on the current density were found. Applying the Lennard–Jones potential we calculated the van der Waals forces between two crossed multi-wall tubes. Tubes detachment conditions are being analyzed.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2008: Materials, Fabrication, Particles, and Characterization – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: June 1, 2008
Pages: 129 - 131
Industry sector: Advanced Materials & Manufacturing
Topics: Carbon Nano Structures & Devices