Current rectification by simple molecular quantum dots: an ab-initio study

Abstract

We calculate a current rectification by molecules containing a conjugated molecular group sandwiched between two saturated (insulating) molecular groups of different length (molecular quantum dot) using an ab-initio non-equilibrium Green's function method. In particular, we study S-(CH2)m-C10H6-(CH2)n-S dithiol with Naphthalene as a conjugated central group. The rectification current ratio ~35 has been observed at m = 2 and n = 10, due to resonant tunneling through the molecular orbital (MO) closest to the electrode Fermi level (lowest unoccupied MO in the present case). The rectification is limited by interference of other conducting orbitals, but can be improved by e.g. adding an electron withdrawing group to the naphthalene.

8 pages, 9 figures

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Cited by in corpus (6)

• Theory of Vibrationally Inelastic Electron Transport through Molecular Bridges
• Current rectification in molecular junctions produced by local potential fields
• The CNT/BCN/CNT structure (zigzag type) as a molecular switch
• Charging effects in biased molecular devices
• Effect of impurities on transport through organic molecular films from first principles
• Coupled cluster theory for the ground and excited states of two dimensional quantum dots