Determination of the light-induced degradation rate of the solar cell sensitizer N719 on TiO2 nanocrystalline particles

Farahnaz Nour-Mohammadi, Sau Doan Nguyen, Gerrit Boschloo, Anders Hagfeldt, Torben Lund

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

    Abstract

    The oxidative degradation rate, kdeg of the solar cell dye (Bu4N+)2 [Ru(dcbpyH)2(NCS)2]2–, referred to as N719 or [RuL2(NCS)2], was obtained by applying a simple model system. Colloidal solutions of N719-dyed TiO2 particles in acetonitrile were irradiated with 532-nm monochromatic light, and the sum of the quantum yields for the oxidative degradation products [RuL2(CN)2], [RuL2(NCS)(CN)], and [RuL2(NCS)(ACN)], deg , were obtained at eight different light intensities in the range of 0.1–16.30 mW/cm2 by LC-UV-MS. The deg values decreased from 3.3 × 10–3 to 2 × 10–4 in the applied intensity range. By using the relation kdeg = deg × kback and back electron transfer reaction rates, kback, obtained using photoinduced absorption spectroscopy, it was possible to calculate an average value for the oxidative degradation rate of N719 dye attached to TiO2 particles, kdeg = 4 × 10–2 s–1. The stability of N719 dye during solar cell operation was discussed based on this number, and on values of the electron transfer rate between [Ru(III) L2(NCS) 2] and iodide that are available in the literature.
    OriginalsprogEngelsk
    TidsskriftJournal of Physical Chemistry B
    Vol/bind109
    Udgave nummer4
    Sider (fra-til)22413-22419
    Antal sider7
    ISSN1520-6106
    DOI
    StatusUdgivet - 2005

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