Patterned growth of ultra long carbon nanotubes. Properties and systematic investigation into their growth process Article

Joshi, R, Schneider, JJ, Yilmazoglu, O et al. (2010). Patterned growth of ultra long carbon nanotubes. Properties and systematic investigation into their growth process . JOURNAL OF MATERIALS CHEMISTRY, 20(9), 1717-1721. 10.1039/b919579c

cited authors

  • Joshi, R; Schneider, JJ; Yilmazoglu, O; Pavlidis, D

authors

abstract

  • High aspect ratio carbon nanotube arrays were grown using a hydrogen/water assisted catalytic chemical vapor deposition method using ethylene as precursor which achieves a growth rate of 25 to 30 μm carbon nanotube length per minute. The influence of the growth parameters determining the growth rate and the growth height of the carbon nanotubes arrays was studied in detail. Water and hydrogen concentration were varied systematically and it was found that they have to be in a precise ratio in order to establish ultralong growth together with high quality (no contamination with carbonaceous side products) of the arranged carbon nanotubes. For given growth conditions, the hydrogen content in the feed gas stream controls the carbon nanotube length, the purity level and the number of graphitic walls of carbon nanotubes grown. It was found that water acts as a weak oxidant keeping the mixed aluminium/iron catalyst active for ultrahigh length growth. Its concentration should be established very precisely in the process to achieve a maximum growth rate of carbon nanotubes. Furthermore a straightforward, non-costly mask technique is presented to achieve highly structured carbon nanotube growth. Finally the field emission characteristics of such ultrahigh, well arranged and structured carbon nanotube blocks was studied and this revealed low turn-on electric and threshold field values of 0.34 V μm-1 and 0.71 V μm-1 respectively. © 2010 The Royal Society of Chemistry.

publication date

  • February 24, 2010

published in

Digital Object Identifier (DOI)

start page

  • 1717

end page

  • 1721

volume

  • 20

issue

  • 9