Electronic Structure Tailoring and Selective Adsorption Mechanism of Metal-coated Nanotubes

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• 作者：Youngmi Cho ; Changwook Kim ; Heesung Moon ; Youngmin Choi ; Sohee Park ; Choong-Ki Lee ; Seungwu Han
• 刊名：Nano Letters
• 出版年：2008
• 出版时间：January 2008
• 年：2008
• 卷：8
• 期：1
• 页码：81 - 86
• 全文大小：372K
• 年卷期：v.8,no.1(January 2008)
• ISSN：1530-6992

文摘

Effects of various metal coating (Co, Ti, Pd, W, and Ru) on electronic structures of carbon nanotubes are systematically studied by both abinitio calculations and field-emission experiments. The theoretical results indicate that the adsorption of metal atoms leads to substantialchanges in the band structures and work functions of nanotubes. In particular, titanium is found to be the most effective coating material forthe application of nanotubes to the field emission display, by lowering the work function and increasing the local density of states near theFermi level. This is confirmed by the field-emission experiments using Ti-coated nanotubes, which shows enhanced emission performances.In addition, it is found that the Ti coating extends the lifetime of the nanotube substantially. Through the thermogravimetric analysis andtheoretical modeling, we propose that this is related to the role of metal coating as a protection layer against residual gases such as oxygen,which cause the degradation of nanotubes. The applications of metal-coated nanotubes to other types of electronic devices are also discussed.