Carbon-nanotube coated cold cathodes for applications to power modulators

Carbon nanotubes were grown on electrodes by means of catalytic thermal chemical vapor deposition in gas mixtures of acetylene and argon. The very large aspect ratio and the very small radius of curvature at the tip of each carbon nanotube are coupled with the highly conductive graphitic walls of carbon nanotubes making them excellent electron field emitters for a wide variety of applications. Electron field emitters serve as cold cathodes and are suitable for replacing hot cathodes that are based on thermionic electron emission for many applications. In this paper, methods of fabricating aligned carbon-nanotube cold cathodes and their electron field emission characteristics and applications for noncontact power coupling, electron controlled switches, and vacuum electronics are discussed.