Authors: J. García-Céspedes, E. Pascual, E. Bertran
Affilation: IN2UB, Universitat de Barcelona, Spain
Pages: 148 - 151
Keywords: PECVD, oriented CNTs, tip-growth, base-growth mechanism
In this work, carbon nanotubes (CNTs) with curly and straight segments were synthesized by means of radio-frequency plasma enhanced chemical vapour deposition (rf-PECVD) onto silicon substrates, using Fe as the catalyst material. The origin of this peculiar combination of aligned and misaligned structures within a singular CNT has been discussed in terms of a simultaneous growth process from the tip and the base of the CNT and taking into account a catalyst interaction with the substrate and carbon diffusion through the growing film. Evidences for supporting such a growth mechanism were found by scanning and transmission electron microscopy studies. The growth kinetics is affected by the particular local conditions surrounding CNTs. A direct comparison between growth rate by PECVD and thermal CVD has been extracted from these samples in our experimental setup based on the proposed growth mechanism.