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Insights into molecular conduction from I-V asymmetry

Avik W. Ghosh·Ferdows Zahid·Prashant S. Damle·Supriyo Datta
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Abstract

We investigate the origin of asymmetry in the measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry. We establish that such molecules can exhibit asymmetric I-V characteristics due to unequal coupling with the contacts. In contrast with spatially asymmetric molecules, conduction takes place through essentially the same level in both bias directions. The asymmetry arises from a subtle difference in the charging effects, which can only be captured in a self-consistent model for molecular conduction. For HOMO-based conduction, the current is smaller for positive voltage on the stronger contact, while for LUMO conduction, the sense of asymmetry is switched.

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Avik W. Ghosh, Ferdows Zahid, Prashant S. Damle, Supriyo Datta. 2002-02-27. Insights into molecular conduction from I-V asymmetry. https://arxiv.org/abs/cond-mat/0202519

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