Dye Regeneration Dynamics by Electron Donors on Mesoscopic TiO2 Films

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• 作者：D. Friedrich ; L. Valldecabres ; M. Kunst ; T. Moehl ; S. M. Zakeeruddin ; M. Gr?tzel
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：February 20, 2014
• 年：2014
• 卷：118
• 期：7
• 页码：3420-3425
• 全文大小：333K
• ISSN：1932-7455

文摘

The influence of different redox mediators and electrolyte constituents on charge transfer processes in dye-sensitized solar cells (DSC) was studied by contactless transient photoconductance (TPC) measurements. Device subsets without FTO (Fluorine-doped tin oxide) contacts were prepared to increase the reliability and sensitivity of the TPC measurements. Results revealed a decrease of electron decay rate with increasing concentration of the redox couple ([Co(III/II)(bpy)<sub>3sub>](PF<sub>6sub>)<sub>3/2sub>) which was attributed to an improvement of the reduction of the dye cation (dye regeneration). Furthermore, the presence of the electrolyte additives 4-tert-butylpyridine (TBP) and chenodeoxycholic acid was found to decrease the electron decay rate, which was attributed to blocking of interfacial charge recombination. The use of other redox couples (quinone/hydroquinone and ferrocene/ferrocenium) with these electrolyte additives displayed a significant improvement for ferrocene/ferrocenium, while the electron lifetime for quinone/hydroquinone appeared unaffected. Prospects for a further optimization of DSC鈥檚 redox couples are discussed.