Transport phenomena of electrons at the carbon nanotube interface with molecular adsorption

The electric conductance of carbon-nanotube (CNT) films is affected by gas adsorption. Previous studies have shown that the adsorption of gas molecules on the CNT/CNT interface is the key to the changing CNT-film conductance. However, it is still unclear how the gas molecules affect the electric con...

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Bibliographic Details
Published in:Journal of applied physics 2017-07, Vol.122 (1)
Main Authors: Kokabu, Takuya, Takashima, Kengo, Inoue, Shuhei, Matsumura, Yukihiko, Yamamoto, Takahiro
Format: Article
Language:English
Subjects:
Adsorption
Applied physics
Carbon nanotubes
Computer simulation
Density functional theory
Electrical conduction
Electron transport
Gas pressure
Permittivity
Resistance
Transport phenomena
Variation
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Summary:The electric conductance of carbon-nanotube (CNT) films is affected by gas adsorption. Previous studies have shown that the adsorption of gas molecules on the CNT/CNT interface is the key to the changing CNT-film conductance. However, it is still unclear how the gas molecules affect the electric conduction of the CNT/CNT interface or its electron transport properties. We present here a study on the effects of gas-molecule adsorption on the CNT/CNT interface using a fluctuation-induced tunneling (FIT) model of the CNT-film electrical conduction. We demonstrated that the CNT-film conduction follows the FIT model, and the subsequently estimated electrostatic potential between the CNT/CNT interfaces was in good agreement with estimates from density functional theory simulations. Since the FIT model treats the CNT/CNT interface as a parallel-plate capacitor, we propose a modified FIT model that accounts for the change in the dielectric constant at the CNT/CNT interface due to the adsorption of gas molecules. This model well explained the electric-conductance change of the CNT film with respect to the gas pressure. Finally, we found that the adsorbed gas molecules affected the local dielectric constant at the CNT/CNT interface.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.4992090