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arXiv · 0804.3637

Alkanethiol-Based Single-Molecule Transistors

Chun-Lan Ma·Diu Nghiem·Yu-Chang Chen
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Abstract

The transport properties of unsubstituted and amino-substituted butanethiol molecules sandwiched between Au electrodes are investigated by using first-principles approaches. New states are observed around the Fermi levels when -NH2 is substituted for -H in the bridging butanethiol. The amino-substituted states lead to a sharp increase of the current which is credited to the resonant tunneling in the junction. We observe a novel conductance peak at VSD = 0.1 V and negative differential resistance (NDR) in a certain range of source-drain bias. In addition to the I-VSD characteristics, we also investigate the current as a function of gate voltage (I-VG) and find that, for a fixed source-drain bias (VSD = 0.01 V), the gate voltage can modulate the conductance by up to 30 times in the amino-substituted butanethiol junction. These I-VG characteristics suggest that the amino-substituted butanethiol molecular junction may be a promising candidate for field-effect transistors.

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Chun-Lan Ma, Diu Nghiem, Yu-Chang Chen. 2008-12-02. Alkanethiol-Based Single-Molecule Transistors. https://doi.org/10.1063/1.3043438

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