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Journal of Nanomaterials
Volume 2013 (2013), Article ID 730952, 5 pages
http://dx.doi.org/10.1155/2013/730952
Research Article

Growth of Carbon Nanotubes on Carbon/Cobalt Films with Different sp2/sp3 Ratios

1School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
2Temasek Laboratories@NTU, 50 Nanyang Avenue, Singapore 639798
3GLOBALFOUNDRIES Singapore Pte. Ltd., Singapore 738406

Received 10 May 2013; Accepted 7 June 2013

Academic Editor: Xingbin Yan

Copyright © 2013 Naiyun Xu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The need of barrier layer such as SiO2 for carbon nanotubes (CNTs) growth limits their performance in electronic applications. In this study, conductive carbon/metal (carbon/cobalt—C:Co) composite films with the same metal content, but different sp2/sp3 ratios, were deposited using dual-source filtered cathodic vacuum arc (FCVA) technique. Three different C:Co composite films were deposited at different temperatures; visible Raman spectroscopy indicates that the sp2-rich C:Co composite film forms at high temperature (500°C), and high-resolution transmission electron microscopy (HRTEM) shows the formation of conducting graphitic-like sp2 clusters and with Co nanoclusters embedded within them. Electrical measurement shows a significant decrease in film resistivity as sp2/sp3 ratio increases. CNTs were successfully grown on the composite films by plasma-enhanced vapor deposition (PECVD) approach. Scanning electron microscopy (SEM) shows minor effect on the density of CNTs by varying the sp2/sp3 ratio. The dependence of defect level of the as-grown CNTs is found to reduce as sp2/sp3 ratio increases.