Growth and structure of carbon nanotubes produced by thermal chemical vapor deposition Original Research Article

Vertically aligned carbon nanotubes are synthesized with high density on a large area of cobalt-deposited silicon oxide substrate by thermal chemical vapor deposition of acetylene at 950°C. The diameters of the carbon nanotubes are distributed in the range 80–120 nm and the length is about 20 μm. The carbon nanotubes have a bamboo-like structure in which the curvature of the compartment is oriented to the tip. The tips are closed and free of encapsulated catalytic particles. The emission current density is 1.1 mA/cm2 at an applied field of about 4.5 V/μm, following the Fowler–Nordheim behavior.