Improvements of Uniformity and Reliability for the Electron Emission of Carbon Nanotubes in High Vacuum Environment

niformity and reliability have been considered as two of the most important issues for the applications of carbon nanotubes infield-emission displays. To improve the uniformity and reliability of carbon nanotubes-based emitters, Fe codeposited with Ti via electron-gun evaporation was utilized as catalyst in a thermal chemical vapor deposition system. The weight percentage of Fe in the codeposited catalyst is 64% and the quantity of Fe is kept the same as compared to a 5-nm pure Fe catalyst. More uniform size and position distribution of nanoparticles were obtained after the pretreatment resulting from the suppression of coalescence between Fe particles. During the pretreatment, the codeposited Ti will merge with the underneath Ti buffer layer and the Ti will hinder the coalescence between Fe nanoparticles. Furthermore, the carbon nanotubes synthesized from the codeposited catalyst exhibited a partially immersed structure which provided a larger contact area between the carbon nanotubes and the substrate to increase the adhesion and reduce the contact resistance. With this way, a uniform electron emission with better reliability from carbon nanotubes was obtained.