| Autor: |
Sharma, Himani, Shukla, A. K., Vankar, V. D. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Aug2011, Vol. 110 Issue 3, p033726, 11p, 1 Illustration |
| Abstrakt: |
The influence of the titanium (Ti) interlayer thickness on the growth and electron emission characteristics of carbon nanotubes (CNTs) deposited on silicon (Si) coated with an iron (Fe) catalyst layer was investigated. Ti films 5 nm, 10 nm, and 15 nm in thickness were deposited beneath the Fe catalyst layers. Multiwalled carbon nanotubes (MWCNTs) were deposited via microwave plasma enhanced chemical vapor deposition. The Ti interlayer hinders the diffusion of Fe into the silicon substrate and thus helps in the growth of MWCNTs. In addition, the role of Ti as a sacrificial layer on the catalytic diffusion, surface morphology, microstructure, and, thus, the growth of MWCNTs was probed through scanning and high resolution transmission electron microscope studies. The enhanced electron emission mechanism as a result of the introduction of a Ti interlayer is explained on the basis of a double barrier model and the formation of a conducting channel between the substrate and the CNTs. The intensified micro-Raman characteristics of the MWCNTs were directly related with the thickness of the Ti interlayer in the three layered system (Ti/Fe/CNT) as compared to a two layer system (Fe/CNT) deposited on a Si substrate. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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