Current rectification by asymmetric molecules: An ab initio study

Yan-hong Zhou; Xiao-hong Zheng; Ying Xu; Zhao Yang Zeng

doi:10.1063/1.2409689

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Current rectification by asymmetric molecules: An ab initio study

Yan-hong Zhou·Xiao-hong Zheng·Ying Xu·Zhao Yang Zeng

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Abstract

We study current rectification effect in an asymmetric molecule HOOC-C$_6$H$_4$-(CH$_2$)$_n$ sandwiched between two Aluminum electrodes using an {\sl ab initio} nonequilibrium Green function method. The conductance of the system decreases exponentially with the increasing number $n$ of CH$_2$. The phenomenon of current rectification is observed such that a very small current appears at negative bias and a sharp negative differential resistance at a critical positive bias when $n\ge 2$. The rectification effect arises from the asymmetric structure of the molecule and the molecule-electrode couplings. A significant rectification ratio of $\sim$38 can be achieved when $n=5$.

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Yan-hong Zhou, Xiao-hong Zheng, Ying Xu, Zhao Yang Zeng. 2006-11-20. Current rectification by asymmetric molecules: An ab initio study. https://doi.org/10.1063/1.2409689

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