Uniform carbon-nanotube emitter for field-emission displays

Abstract

— The synthesis of carbon-nanotube (CNT) field emitters for FEDs by thermal chemical vapor deposition (CVD) and their structural and emission characterization are described. Multi-walled nanotubes (MWNTs) were grown on patterned metal-base electrodes by thermal CVD, and the grown CNTs formed a network structured layer covering the surfaces of the metal electrode uniformly, which realized uniform distribution of electron emission. A technique for growing narrow MWNTs was also developed in order to reduce the driving voltage. The diameter of MWNT depends on the growth temperature, and it has changed from 40 nm at the low temperature (675°C) to 10–15 nm at the high temperature (900–1000°C). Moreover, narrower MWNTs were grown by using the metal-base electrode covered with a thin alumina layer and a metal catalyst layer. Double-walled nanotubes (DWNTs) were also observed among narrow MWNTs. The emission from the narrow CNTs showed a low turn-on electric field of 1.5 V/μm at the as-grown layer.