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Gating of a molecular transistor: Electrostatic and Conformational

Avik W. Ghosh·Titash Rakshit·Supriyo Datta
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Abstract

We derive a general result that can be used to evaluate and compare the transconductance of different field-effect mechanisms in molecular transistors, both electrostatic and conformational. The electrostatic component leads to the well-known thermal limit in the absence of tunneling. We show that in a standard three-terminal geometry and in the absence of strong electron-phonon coupling, the conformational component can lead to significant advantages only if the molecular dipole moment \mu is comparable to et_ox, t_ox being the thickness of the oxide. Surprisingly this conclusion is independent of the ``softness'' of the conformational modes involved, or other geometrical factors. Detailed numerical results for specific examples are presented in support of the analytical results.

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Avik W. Ghosh, Titash Rakshit, Supriyo Datta. 2002-12-08. Gating of a molecular transistor: Electrostatic and Conformational. https://arxiv.org/abs/cond-mat/0212166

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