Current Rectification through π–π Stacking in Multilayered Donor–Acceptor Cyclophanes

Abstract

Extended π-stacked molecules have attracted much attention since they play an essential role in both electronic devices and biological systems. In this article electron transport properties of a series of multilayered cyclophanes with the hydroquinone donor and quinone acceptor units in the external positions are theoretically studied with applications to molecular rectifiers in mind. Calculations of electron transport through the π–π stacked structures in the multilayered cyclophanes are performed by using nonequilibrium Green’s function method combined with density functional theory. Calculated transmission spectra show that the conductance decreases exponentially with the length of the molecule with a decay factor of 0.75 A–1, which lies for the values between π-conjugated molecules and σ-bonded molecules. Applied bias calculations provide current–voltage curves, which exhibit good rectifying behavior. The rectification mechanism in the coherent transport regime is qualitatively explained by the respon...