Rapid Growth of Vertically Aligned Carbon Nanotubes

100-µm-long vertically aligned multiwall carbon nanotubes were grown in 1 s. A thermal chemical vapor deposition method at 700°C was used with a catalyst of iron films and a carbon source gas of acetylene diluted with helium. This study revealed a novel rapid growth mode that appears in the beginning of chemical vapor deposition when the rate of increase in the concentration of carbon source gas is high at the substrate. This new growth mode, which precedes a normal growth mode, provides well-crystallized and straight nanotubes.