title: Light-Induced Switching of Tunable Single-Molecule Junctions.
abstract: A major goal of molecular electronics is the development and implementation of devices such as single-molecular switches. Here, measurements are presented that show the controlled in situ switching of diarylethene molecules from their nonconductive to conductive state in contact to gold nanoelectrodes via controlled light irradiation. Both the conductance and the quantum yield for switching of these molecules are within a range making the molecules suitable for actual devices. The conductance of the molecular junctions in the opened and closed states is characterized and the molecular levelE0, which dominates the current transport in the closed state, and its level broadeningΓare identified. The obtained results show a clear light-induced ring forming isomerization of the single-molecule junctions. Electron withdrawing side-groups lead to a reduction of conductance, but do not influence the efficiency of the switching mechanism. Quantum chemical calculations of the light-induced switching processes correlate these observations with the fundamentally different low-lying electronic states of the opened and closed forms and their comparably small modification by electron-withdrawing substituents. This full characterization of a molecular switch operated in a molecular junction is an important step toward the development of real molecular electronics devices.
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 400 01328 Dresden Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Sendler
authors.affiliation: Department of Physics Universität Konstanz 78457 Konstanz Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Luka-Guth
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 400 01328 Dresden Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wieser
authors.affiliation: Institute for Materials Science and Max Bergmann Center of Biomaterials Dresden Technische Universität Dresden 01062 Dresden Germany.
authors.lastname: Lokamani
authors.affiliation: Fachbereich Chemie Universität Konstanz 78457 Konstanz Germany.
authors.forename: Jannic
authors.initials: J
authors.lastname: Wolf
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 40001328 Dresden Germany; Center for Advancing Electronics Dresden Technische Universität Dresden 01062 Dresden Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Helm
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 40001328 Dresden Germany; Faculty of Science Technische Universität Chemnitz 09107 Chemnitz Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Gemming
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 40001328 Dresden Germany; Center for Advancing Electronics Dresden Technische Universität Dresden 01062 Dresden Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Kerbusch
authors.affiliation: Department of Physics Universität Konstanz 78457 Konstanz Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Scheer
authors.affiliation: Fachbereich Chemie Universität Konstanz 78457 Konstanz Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Huhn
authors.affiliation: Helmholtz-Zentrum Dresden - Rossendorf Bautzner Landstraße 400 01328 Dresden Germany.
authors.forename: Artur
authors.initials: A
authors.lastname: Erbe
keywords: diarylethenes; in situ switching; molecular electronics; photochromism; single‐molecule junctions