Growth behavior of carbon nanotubes on Fe-deposited (001) Si substrates

Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to investigate the growth behavior of carbon nanotubes on the Fe-deposited Si (001) substrates by thermal chemical vapor deposition (CVD). The Fe films are deposited for 20 s-20 min by pulse-laser deposition. SEM results show that the growth characteristics of carbon nanotubes strongly depend on the Fe film deposition time. TEM results show that the CVD growth at 800°C causes the continuous Fe films to be broken up into nanoparticles 10-50 nm across and discontinuous islands 100 nm-1.1 μm in size. It is shown that the Fe nanoparticles are essentially required for the formation of aligned carbon nanotubes. We show direct evidence that a base growth mode is responsible for the growth of carbon nanotubes in the present work.