High on-off conductance switching ratio in optically-driven self-assembled conjugated molecular systems

Abstract

A new azobenzene-thiophene molecular switch is designed, synthesized and used to form self-assembled monolayers (SAM) on gold. An "on/off" conductance ratio up to 7x1E3 (with an average value of 1.5x1E3) is reported. The "on" conductance state is clearly identified to the cis isomer of the azobenzene moiety. The high "on/off" ratio is explained in terms of photo-induced, configuration-related, changes in the electrode-molecule interface energetics (changes in the energy position of the molecular orbitals with respect to the Fermi energy of electrodes) in addition to changes in the tunnel barrier length (length of the molecules). First principles DFT calculations demonstrate a better delocalization of the frontier orbitals, as well as a stronger electronic coupling between the azobenzene moiety and the electrode for the cis configuration over the trans one. Measured photoionization cross-sections for the molecules in the SAM are close to the known values for azobenzene derivatives in solution.

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References in corpus (5)

• Driving current through single organic molecules
• Reversible Photomechanical Switching of Individual Engineered Molecules at a Surface
• Coherent electron transport through an azobenzene molecule: A light-driven molecular switch
• Tuning the conductance of a molecular switch
• Molecular rectifying diodes from self-assembly on silicon

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