Oligothiophene‐Based Phosphonates for Surface Modification of Ultraflat Transparent Conductive Oxides

Advanced Materials Interfaces, vol. 7

Abstract

Abstract The self‐assembly of electroactive organic molecules on transparent conductive oxides is a versatile strategy to engineer the interfacial energy‐level alignment and to enhance charge carrier injection in optoelectronic devices. Via chemical grafting of an aromatic oligothiophene molecule by changing the position of the phosphonic acid anchoring group with respect to the organic moiety (terminal and internal), the direction of the main molecular dipole is changed, i.e., from parallel to perpendicular to the substrate, to study the molecular arrangement and electronic properties at the organic–inorganic interface. It is found that the observed work function increase cannot solely be predicted based on the calculated molecular dipole moment of the oligothiophene‐based phosphonates. In addition, charge transfer from the substrate to the molecule has to be taken into account. Molecular assembly and induced electronic changes are analogous for both indium‐tin oxide (ITO) and zinc oxide (ZnO), demonstrating the generality of the approach and highlighting the direct correlation between molecular coverage and electronic effects.

Authors 10

1. Melanie Timpel corresponding

   Humboldt-Universität zu Berlin · Institute of Materials for Electronics and Magnetism

   Affiliation as printed

   Institut für Physik & IRIS Adlershof Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 6 Berlin 12489 Germany

   Istituto dei Materiali per l'Elettronica ed il Magnetismo IMEM‐CNR Sezione di Trento Via alla Cascata 56/C (Povo) Trento 38123 Italy

   Istituto dei Materiali per l'Elettronica ed il Magnetismo, IMEM-CNR, Sezione di Trento, Via alla Cascata 56/C (Povo), Trento, 38123 Italy

2. Marco Vittorio Nardi corresponding

   Humboldt-Universität zu Berlin · Institute of Materials for Electronics and Magnetism

   Affiliation as printed

   Institut für Physik & IRIS Adlershof Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 6 Berlin 12489 Germany

   Istituto dei Materiali per l'Elettronica ed il Magnetismo IMEM‐CNR Sezione di Trento Via alla Cascata 56/C (Povo) Trento 38123 Italy

   Istituto dei Materiali per l'Elettronica ed il Magnetismo, IMEM-CNR, Sezione di Trento, Via alla Cascata 56/C (Povo), Trento, 38123 Italy

3. Berthold Wegner

   Humboldt-Universität zu Berlin

   Affiliation as printed

   Institut für Physik & IRIS Adlershof Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 6 Berlin 12489 Germany

4. Giovanni Ligorio

   Humboldt-Universität zu Berlin

   Affiliation as printed

   Institut für Physik & IRIS Adlershof Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 6 Berlin 12489 Germany

5. Luca Pasquali

   University of Modena and Reggio Emilia · University of Johannesburg · AREA Science Park

   Affiliation as printed

   Department of Physics University of Johannesburg PO Box 524 Auckland Park 2006 South Africa

   Engineering Department “E. Ferrari” University of Modena e Reggio Emilia Via Vivarelli 10 Modena 41125 Italy

   IOM‐CNR Institute Area Science Park SS 14 Km, 163.5, Basovizza Trieste 34149 Italy

   Engineering Department “E. Ferrari” University of Modena e Reggio Emilia Via Vivarelli 10 Modena 41125 Italy

   IOM-CNR Institute, Area Science Park, SS 14 Km, 163.5, Basovizza, Trieste, 34149 Italy

6. Jana Hildebrandt

   Humboldt-Universität zu Berlin

   Affiliation as printed

   Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 2 Berlin 12489 Germany

7. Michael Pätzel

   Humboldt-Universität zu Berlin

   Affiliation as printed

   Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 2 Berlin 12489 Germany

8. Stefan Hecht Aachen DWI ‐ Leibniz‐Institut für Interaktive Materialien e.V Institut für Technische und Makromolekulare Chemie

   Humboldt-Universität zu Berlin · DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI – Leibniz Institut für Interaktive Materialien e.V. RWTH Aachen University Forckenbeckstraße 50 Aachen 52056 Germany

   Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 2 Berlin 12489 Germany

   Institut für Technische und Makromolekulare Chemie RWTH Aachen University Worringerweg 2 Aachen 52074 Germany

9. Hiromichi Ohta

   Hokkaido University

   Affiliation as printed

   Research Institute for Electronic Science Hokkaido University N20W10 Sapporo 001‐0020 Japan

   Research Institute for Electronic Science, Hokkaido University, N20W10, Sapporo, 001-0020 Japan

10. Norbert Koch

    Helmholtz-Zentrum Berlin für Materialien und Energie · Soochow University · Humboldt-Universität zu Berlin

    Affiliation as printed

    Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH Albert‐Einstein‐Str. 16 Berlin 12489 Germany

    Institut für Physik & IRIS Adlershof Humboldt‐Universität zu Berlin Brook‐Taylor‐Str. 6 Berlin 12489 Germany

    Jiangsu Key Laboratory for Carbon Based Functional Materials and Devices and Institute of Functional Nano and Soft Materials (FUNSOM) Soochow University 199 Ren‐Ai Road Suzhou 215123 China

    Jiangsu Key Laboratory for Carbon Based Functional Materials and Devices and Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou, 215123 China