Molecular-Scale Interface Engineering of Nanocrystalline Titania by Co-adsorbents for Solar Energy Conversion

Authors

  • Dr. Mingkui Wang,

    1. Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, College of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (PR China)
    2. Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
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  • Stefan Plogmaker,

    1. Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden)
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  • Dr. Robin Humphry-Baker,

    1. Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
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  • Dr. Peter Pechy,

    1. Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
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  • Prof. Håkan Rensmo,

    Corresponding author
    1. Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden)
    • Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden)
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  • Dr. Shaik. M. Zakeeruddin,

    Corresponding author
    1. Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
    • Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
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  • Prof. Michael Grätzel

    Corresponding author
    1. Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
    • Laboratory for Photonics and Interfaces, Swiss Federal Institute of Technology, 1015, Lausanne (Switzerland), Fax: (+41) 21-6934111
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Abstract

The use of mixed self-assembled monolayers, combining hydrophobic co-adsorbents with the sensitizer, has been demonstrated to enhance the efficiency of dye-sensitized solar cells (DSCs). Herein, the influence of the anchoring groups of the co-adsorbents on the performance of the DSCs is carefully examined by selecting two model molecules: neohexyl phosphonic acid (NHOOP) and bis-(3,3-dimethyl-butyl)-phosphinic acid (DINHOP). The effect of these co-adsorbents on the photovoltaic performance (JV curves, incident photon-to-electron conversion efficiency) is investigated. Photoelectron spectroscopy and electrochemical impedance spectroscopy are performed to assess the spatial configuration of adsorbed dye and co-adsorbent molecules. The photoelectron spectroscopy studies indicate that the ligands of the ruthenium complex, containing thiophene groups, point out away from the surface of TiO2 in comparison with the NCS group.

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