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arXiv · 2011.08953

Covalent Grafting of Polyoxometalate Hybrids onto Flat Silicon/Silicon Oxide: Insights from POMs Layers on Oxides

Maxime Laurans·Kelly Trinh·Kevin Dalla Francesca·Guillaume Izzet·Sandra Alves·Etienne Derat·Vincent Humblot·Olivier Pluchery·Dominique Vuillaume·Stéphane Lenfant·Florence Volatron·Anna Proust
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Abstract

Immobilization of polyoxometalates (POMs) onto oxides is relevant to many applications in the fields of catalysis, energy conversion/storage or molecular electronics. Optimization and understanding the molecule/oxide interface is crucial to rationally improve the performance of the final molecular materials. We herein describe the synthesis and covalent grafting of POM hybrids with remote carboxylic acid functions onto flat Si/SiO2 substrates. Special attention has been paid to the characterization of the molecular layer and to the description of the POM anchoring mode at the oxide interface through the use of various characterization techniques, including ellipsometry, AFM, XPS and FTIR. Finally, electron transport properties were probed in a vertical junction configuration and energy level diagrams have been drawn and discussed in relation with the POM molecular electronic features inferred from cyclic-voltammetry, UV-visible absorption spectra and theoretical calculations. The electronic properties of these POM-based molecular junctions are driven by the POM LUMO (d-orbitals) whatever the nature of the tether or the anchoring group.

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Maxime Laurans, Kelly Trinh, Kevin Dalla Francesca, Guillaume Izzet, Sandra Alves, Etienne Derat, Vincent Humblot, Olivier Pluchery, Dominique Vuillaume, Stéphane Lenfant, Florence Volatron, Anna Proust. 2020-11-17. Covalent Grafting of Polyoxometalate Hybrids onto Flat Silicon/Silicon Oxide: Insights from POMs Layers on Oxides. https://doi.org/10.1021/acsami.0c12300.s001

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