Carbon nanotubes, substrate and electron emission device with such carbon nanotubes and carbon nanotube synthesizing substrate as well as methods of and apparatus for making them

Abstract

A novel carbon nanotube (64) is featured in that it has the highest Raman scattering intensity in the vicinity of 1580 cm−1 in its Raman spectrum. Carbon nanotubes can be grown on and from the catalytic fine particles (63) which consist of ultra-fine particles of cobalt oxide catalyst onto a substrate comprising a conductive substrate (62) and fine particles (63) of catalyst formed on a surface thereof. An electron emission device (60) so configured as to emit electrons by applying a voltage to apical ends (64a) of such carbon nanotubes (64) can be reduced in driving voltage and can achieve a current such as to emit a fluorescent material on the market for low-velocity electron beams. The electron emission device (60) needs no gate and can thus simplify the structure and reduce the cost of a surface light-emitting device for which the element is used. The carbon material remains unoxidized even in a low vacuum and thus allows realizing a light emitting device that can be paneled more easily, and is longer in operating life than those using a conventional electron emission device.

Dependencies are inferred from the claim text.