Investigation of the growth mechanisms and electron emission properties of carbon nanostructures prepared by hot-filament chemical vapour deposition

We have investigated the feasibility of the hot-filament chemical vapour deposition (HFCVD) technique to synthesise carbon nanostructures with attractive electron emission properties on nickel and cobalt thin films and dots. For this purpose, a systematic study of the influence of deposition conditions on both growth morphology and emission characteristics was undertaken and complemented by micro-Raman characterisations. Depending on the substrate preparation and synthesis conditions, carbon nanostructures with completely different growth morphologies were prepared. In particular, we have highlighted the peculiarity of the HFCVD technique to favour an oriented and coral-like growth mode of a complex material composed essentially of carbon nanotubes and nanoparticles. By this means, a threshold electric field as low as 4 V μm −1 has been reached for a deposition temperature compatible with glass panels.