The Effects of Embedded Dipoles in Aromatic Self‐Assembled Monolayers |
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| Authors: | Tarek Abu‐Husein Swen Schuster Martin Kind Tobias Santowski Adrian Wiesner Ryan Chiechi Egbert Zojer Andreas Terfort Michael Zharnikov |
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| Affiliation: | 1. Institut für Anorganische und Analytische Chemie, Universit?t Frankfurt, Frankfurt, Germany;2. Angewandte Physikalische Chemie, Universit?t Heidelberg, Heidelberg, Germany;3. Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, AG, Groningen, The Netherlands;4. Institute of Solid State Physics, NAWI Graz, Graz University of Technology, Graz, Austria |
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| Abstract: | Using a representative model system, here electronic and structural properties of aromatic self‐assembled monolayers (SAMs) are described that contain an embedded, dipolar group. As polar unit, pyrimidine is used, with its orientation in the molecular backbone and, consequently, the direction of the embedded dipole moment being varied. The electronic and structural properties of these embedded‐dipole SAMs are thoroughly analyzed using a number of complementary characterization techniques combined with quantum‐mechanical modeling. It is shown that such mid‐chain‐substituted monolayers are highly interesting from both fundamental and application viewpoints, as the dipolar groups are found to induce a potential discontinuity inside the monolayer, electrostatically shifting the core‐level energies in the regions above and below the dipoles relative to one another. These SAMs also allow for tuning the substrate work function in a controlled manner independent of the docking chemistry and, most importantly, without modifying the SAM‐ambient interface. |
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| Keywords: | interface control molecular dipole self‐assembled monolayers work function |
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