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Effect of ion bombardment on the synthesis of vertically aligned single-walled carbon nanotubes by plasma-enhanced chemical vapor deposition.

Research paper by Zhiqiang Z Luo, Sanhua S Lim, Yumeng Y You, Jianmin J Miao, Hao H Gong, Jixuan J Zhang, Shanzhong S Wang, Jianyi J Lin, Zexiang Z Shen

Indexed on: 25 Jun '08Published on: 25 Jun '08Published in: Nanotechnology



Abstract

The synthesis of vertically aligned single-walled carbon nanotubes (VA-SWNTs) by plasma-enhanced chemical vapor deposition (PECVD) was achieved at 500-600 °C, using ethylene as the carbon source and 1 nm Fe film as the catalyst. For growth of high-quality VA-SWNTs in a plasma sheath, it is crucial to alleviate the undesirable ion bombardment etching effects by the optimization of plasma input power and gas pressure. The resistibility of synthesized VA-SWNTs against ion bombardment etching was found to be closely related to the growth temperature. At relatively low temperature (500 °C), the VA-SWNTs were very susceptible to ion bombardments, which could induce structural defects, and even resulted in a structural transition to few-walled nanotubes. For capacitively coupled radio frequency (rf) PECVD operating at moderate gas pressure (0.3-10 Torr), the ion bombardment etching effect is mainly dependent on the ion flux, which is related to the plasma input power and gas pressure.