Abstract
Vertically aligned single-walled carbon nanotubes (SWCNTs) can be fabricated on the Co/Si(100) substrate in a gravity assisted chemical vapor deposition process. The Co/Si(100) substrate is tilted such that its surface normal points downwards in the chemical vapor deposition process. All the SWCNTs are lined up with the direction of gravity. The length of SWCNTs increases with growth time. A modified vapor-liquid-solid mechanism is proposed to explain the role of gravity in the precipitation of SWCNTs and in the lineup behavior of SWCNTs. © 2006 American Institute of Physics.