Efficient field emission of carbon nanotubes grown on a copper substrate

Carbon nanotubes have been grown on a polished copper substrate by thermal chemical vapor deposition (CVD). Nickel film is deposited on the metallic substrate as catalyst and the reactant gas is acetylene. Efficient field emission of CNTs emitters (Emission area is about 3.14 mm
²
) is observed from I-V and F-N curves. Stable emission current with the density of more than 20mA was got at the electric field of 2.87V/um. SEM and TEM were used to characterize the morphologies of carbon nanotubes.