Superlong-oriented Single-Walled Carbon Nanotube Arrays on Substrate with Low Percentage of Metallic Structure

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• 作者：Yong Qian ; Shaoming Huang ; Fenglei Gao ; Qiran Cai ; Lijie Zhang ; Wenbing Hu
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：April 30, 2009
• 年：2009
• 卷：113
• 期：17
• 页码：6983-6988
• 全文大小：289K
• 年卷期：v.113,no.17(April 30, 2009)
• ISSN：1932-7455

文摘

We report in this paper a convenient and effective method to identify the structures of superlong well-aligned single-walled carbon nanotubes (SWNTs) via the combination of electrodeposition of Ag particles on the SWNTs with Raman spectroscopy. The suitable density and the visibility of the Ag-deposited long nanotubes make it possible to acquire Raman spectra from isolated individual long nanotubes very easily. The results reveal that the superlong well-oriented SWNT arrays on SiO₂/Si wafer fabricated by EtOH-CVD using Fe/Mo nanoparticles as catalyst exhibit a lower percentage of metallic SWNTs (m-SWNTs) (5%). Among other SWNTs, 62% are semiconducting SWNTs (s-SWNTs) and 32% are so-called quasi-insulators, which are believed to be caused inevitably by the defects during growth process. Small amount of nanotubes are so-called quasi-metallic. Furthermore, the structural uniformity of the long SWNTs can be also evaluated by the deposition of Ag along the length and Raman spectroscopy. Besides, on the basis of the in situ laser irradiation on individual SWNTs, it was found that s-SWNT is more stable than m-SWNT. The m-SWNT can be changed to s-SWNT under laser beam with an appropriate conditions, providing a facile method to generate alternative m- and s-SWNT multiple junction on one individual long SWNT, which may have special electrical properties and potential applications in nanoelectronics.