S Darbari - Thin Film and Nanoelectronic Lab, ECE Department, University of Tehran, Tehran, Iran
Y Abdi - Thin Film and Nanoelectronic Lab, ECE Department, University of Tehran, Tehran, Iran. Department of physics, University of Tehran, Tehran, Iran.
S Mohajerzadeh - Thin Film and Nanoelectronic Lab, ECE Department, University of Tehran, Tehran, Iran.

Vertically aligned carbon nanotubes (CNTs) have been grown on silicon substrates using nickel as the catalyst layer. A tip-growth mechanism with an inner tube diameter of 5–8 nm was observed. The effect of plasma hydrogenation as a post-growth treatment was shown to lead to partial removal of the nickel seeds from the CNT tips. Using sequential hydrogenation and growth, it has been possible to achieve tree-like nanostructures. SEM analysis was used to show growth mechanism of as grown branched carbon nanostructures.

Branched carbon nanostructures, PECVD, nanotube