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 () is featured in that it has the highest Raman scattering intensity in the vicinity of 1580 cmin its Raman spectrum. Carbon nanotubes can be grown on and from the catalytic fine particles () which consist of ultra-fine particles of cobalt oxide catalyst onto a substrate comprising a conductive substrate () and fine particles () of catalyst formed on a surface thereof. An electron emission device () so configured as to emit electrons by applying a voltage to apical ends () of such carbon nanotubes () 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 () 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.