High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes

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Dye-sensitized solar cells based on iodide/triiodide (I/I3) electrolytes are viable low-cost alternatives to conventional silicon solar cells. However, as well as providing record efficiencies of up to 12.0%, the use of I/I3 in such solar cells also brings about certain limitations that stem from its corrosive nature and complex two-electron redox chemistry. Alternative redox mediators have been investigated, but these generally fall well short of matching the performance of conventional I/I3 electrolytes. Here, we report energy conversion efficiencies of 7.5% (simulated sunlight, AM1.5, 1,000 W m−2) for dye-sensitized solar cells combining the archetypal ferrocene/ferrocenium (Fc/Fc+) single-electron redox couple with a novel metal-free organic donor–acceptor sensitizer (Carbz-PAHTDTT). These Fc/Fc+-based devices exceed the efficiency achieved for devices prepared using I/I3 electrolytes under comparable conditions, revealing the great potential of ferrocene-based electrolytes in future dye-sensitized solar cells applications. This improvement results from a more favourable matching of the redox potential of the ferrocene couple with that of the new donor–acceptor sensitizer.

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Figure 1: Energy levels of DSC components, approximate redox potentials and band energies of the different components.
Figure 2
Figure 3: IPCE results and absorptivity of the Carbz-PAHTDTT sensitized TiO2 film.
Figure 4
Figure 5: Photocurrent density–voltage curves at simulated one sun (1,000 W m−2) irradiation (AM1.5).
Figure 6: IMVS and IMPS spectroscopy.


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The authors acknowledge financial support from the Australian Research Council through the Australian Centre of Excellence for Electromaterials Science (ACES), and the Discovery, Australian Research Fellowship and LIEF programs, the Commonwealth Scientific and Industrial Research Organisation (Australia), the Victorian State Government Department of Primary Industry (SERD Program, Victorian Organic Solar Cells Consortium) and Monash University (supporting U.B. with a Monash Research Fellowship). Particular thanks go to JGC Catalysts and Chemicals Ltd, Kitakyushu-Shi (Japan), for providing samples of TiO2 screen printing paste.

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L.S., U.B. and A.B.H. proposed the research. T.D. designed the electrolyte, developed the construction technique, fabricated the DSCs and carried out device characterization. T.-H.K. designed, synthesized and characterized the dye. N.W.D. and T.D. carried out the charge extraction and IMVS–IMPS measurements on instruments designed by N.W.D. L.S., U.B. and T.D. were mainly responsible for writing the manuscript, with contributions from N.W.D., T.-H.K. and A.B.H.

Correspondence to Udo Bach or Leone Spiccia.

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Daeneke, T., Kwon, T., Holmes, A. et al. High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes. Nature Chem 3, 211–215 (2011) doi:10.1038/nchem.966

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