Multi-Walled Carbon Nanotubes Growing Vertically from Root Particles

Abstract

The catalytic growth of multi-walled carbon nanotubes (MWCNTs) was performed on Si substrates with and without interfacial layers, by microwave plasma chemical vapor deposition (MPCVD). Many vertically grown, dense MWCNTs attached to a catalytic film penetrated the root particles. The diameter of root particles, in the order of 100 nm, is larger than the tube diameters of 10-15 nm. Base growth and tip growth are proposed as part of a new CNT growth model. The interaction between catalytic film and the supporting interfacial layer is suggested to determine whether the catalytic particles are driven up or pinned down on the substrate during the growth. (C) 2010 The Japan Society of Applied Physics