Current rectification by asymmetric molecules: An ab initio study

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 $n=5$.

to appear in J. Chem. Phys

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Cited by in corpus (1)

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