title: Tuning the Rectification Ratio by Changing the Electronic Nature (Open-Shell and Closed-Shell) in Donor-Acceptor Self-Assembled Monolayers.
abstract: This Communication describes the mechanism of charge transport across self-assembled monolayers (SAMs) of two donor-acceptor systems consisting of a polychlorotriphenylmethyl (PTM) electron-acceptor moiety linked to an electron-donor ferrocene (Fc) unit supported by ultraflat template-stripped Au and contacted by a eutectic alloy of gallium and indium top contacts. The electronic and supramolecular structures of these SAMs were well characterized. The PTM unit can be switched between the nonradical and radical forms, which influences the rectification behavior of the junction. Junctions with nonradical units rectify currents via the highest occupied molecular orbital (HOMO) with a rectification ratio R = 99, but junctions with radical units have a new accessible state, a single-unoccupied molecular orbital (SUMO), which turns rectification off and drops R to 6.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)/CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Manuel
authors.identifier: 0000-0003-3491-6984
authors.initials: M
authors.lastname: Souto
authors.affiliation: Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Li
authors.initials: L
authors.lastname: Yuan
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)/CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Dayana C
authors.initials: DC
authors.lastname: Morales
authors.affiliation: Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)/CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Imma
authors.identifier: 0000-0002-1464-9789
authors.initials: I
authors.lastname: Ratera
authors.affiliation: Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.|Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546, Singapore.
authors.forename: Christian A
authors.identifier: 0000-0003-3435-4600
authors.initials: CA
authors.lastname: Nijhuis
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)/CIBER-BBN, Campus de la UAB, 08193 Bellaterra, Spain.
authors.forename: Jaume
authors.identifier: 0000-0003-1023-9923
authors.initials: J
authors.lastname: Veciana