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Equivalent Circuit Modeling for Carbon Nanotube Schottky Barrier Modulation in Polarized GasesWe study the carbon nanotube Schottky barrier at the metallic electrode interface in polarized gases using an equivalent circuit model. The gas-nanotube interaction is often weak and very little charge transfer is expected [l]. This is the case with'oxygen, but the gas-electrode interaction is appreciable and makes the oxygen molecules negatively charged. In the closed circuit condition, screening positive charges appear in the nanotube as well as in the electrode, and the Schottky barrier is modulated due to the resultant electrostatic effects [2]. In the case of ammonia, both the gas-nanotube and gas-electrode interactions are weak, but the Schottky barrier can still be modulated since the molecules are polarized and align in the preferred orientation within the gap between the electrode and nanotube in the open circuit condition (dipole layer formation). In the closed circuit condition, an electric field appears in the gap and strengthens or weakens the preferred dipole alignment reflecting the nanotube Fermi level. The modulation is visible when the nanotube depletion mode is involved, and the required dipole density is as low as 2 x 10(exp 13) dipoles/sq cm, which is quite feasible experimentally,
Document ID
20050184196
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Yamada, Toshishige
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Electronics And Electrical Engineering
Meeting Information
Meeting: American Physical Society Meeting
Location: Los Angeles, CA
Country: United States
Start Date: March 21, 2005
End Date: March 25, 2005
Sponsors: American Physical Society
Funding Number(s)
CONTRACT_GRANT: NAS2-03144
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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