Publication

Mixed Monolayers of Spiropyrans Maximize Tunneling Conductance Switching by Photoisomerization at the Molecule-Electrode Interface in EGaIn Junctions

Kumar, S., van Herpt, J. T., Gengler, R. Y. N., Feringa, B. L., Rudolf, P. & Chiechi, R. C., 28-Sep-2016, In : Journal of the American Chemical Society. 138, 38, p. 12519-12526 7 p.

Research output: Contribution to journalArticleAcademicpeer-review

Copy link to clipboard

Documents

  • Mixed Monolayers of Spiropyrans Maximize Tunneling Conductance Switching

    Final publisher's version, 1.46 MB, PDF document

    Request copy

DOI

This paper describes the photo-induced switching of conductance in tunneling junctions comprising self-assembled monolayers of a spiropyran moiety using eutectic Ga-In top contacts. Despite separation of the spiropyran unit from the electrode by a long alkyl ester chain, we observe an increase in the current density J of a factor of 35 at 1 V when the closed form is irradiated with UV light to induce the ring-opening reaction, one of the highest switching ratios reported for junctions incorporating self-assembled monolayers. The magnitude of switching of hexanethiol mixed-monolayers was higher than that of pure spiropyran monolayers. The first switching event recovers 100% of the initial value of J and, in the mixed-monolayers, subsequent dampening is not the result of degradation of the monolayer. The observation of increased conductivity is supported by zero-bias DFT calculations showing a change in the localization of the density of states near the Fermi level as well as by simulated transmission spectra revealing positive resonances that broaden and shift towards the Fermi level in the open form.

Original languageEnglish
Pages (from-to)12519-12526
Number of pages7
JournalJournal of the American Chemical Society
Volume138
Issue number38
Publication statusPublished - 28-Sep-2016

    Keywords

  • SELF-ASSEMBLED MONOLAYERS, EUTECTIC GA-IN, CHARGE-TRANSPORT, INJECTION CURRENT, EMBEDDED DIPOLES, METAL JUNCTIONS, GOLD SURFACES, TOP-CONTACTS, LIGHT, RECTIFICATION

ID: 35360141