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.
Subscribe to Journal
Get full journal access for 1 year
only $14.08 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
O'Regan, B. & Grätzel, M. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 353, 737–740 (1991).
Chen, C.-Y. et al. Highly efficient light-harvesting ruthenium sensitizer for thin-film dye-sensitized solar cells. ACS Nano 3, 3103–3109 (2009).
Zeng, W. et al. Efficient dye-sensitized solar cells with an organic photosensitizer featuring orderly conjugated ethylenedioxythiophene and dithienosilole blocks. Chem. Mater. 22, 1915–1925 (2010).
Yu, Q. et al. High-efficiency dye-sensitized solar cells: The influence of lithium ions on exciton dissociation, charge recombination, and surface states. ACS Nano 4, 6032–6038 (2010).
Boschloo, G. & Hagfeldt, A. Characteristics of the iodide/triiodide redox mediator in dye-sensitized solar cells. Acc. Chem. Res. 42, 1819–1826 (2009).
Zhang, Z., Chen, P., Murakami, T. N., Zakeeruddin, S. M. & Grätzel, M. The 2,2,6,6-tetramethyl-1-piperidinyloxy radical: an efficient, iodine-free redox mediator for dye-sensitized solar cells. Adv. Funct. Mater. 18, 341–346 (2008).
Schlichthoerl, G., Huang, S. Y., Sprague, J. & Frank, A. J. Band edge movement and recombination kinetics in dye-sensitized nanocrystalline TiO2 solar cells: a study by intensity modulated photovoltage spectroscopy. J. Phys. Chem. B 101, 8141–8155 (1997).
Gregg, B. A., Pichot, F., Ferrere, S. & Fields, C. L. Interfacial recombination processes in dye-sensitized solar cells and methods to passivate the interfaces. Phys. Chem. B 105, 1422–1429 (2001).
Ardo, S. & Meyer, G. J. Photodriven heterogeneous charge transfer with transition-metal compounds anchored to TiO2 semiconductor surfaces. Chem. Soc. Rev. 38, 115–164 (2009).
Hagfeldt, A., Boschloo, G., Sun, L., Kloo, L. & Pettersson, H. Dye-sensitized solar cells. Chem. Rev. 110, 6595–6663 (2010).
Yanagida, S., Yu, Y. & Manseki, K. Iodine/iodide-free dye-sensitized solar cells. Acc. Chem. Res. 42, 1827–1838 (2009).
Nusbaumer, H., Moser, J.-E., Zakeeruddin, S. M., Nazeeruddin, M. K. & Grätzel, M. CoII(dbbip)22+ complex rivals tri-iodide/iodide redox mediator in dye-sensitized photovoltaic cells. J. Phys. Chem. B 105, 10461–10464 (2001).
Feldt, S. M. et al. Design of organic dyes and cobalt polypyridine redox mediators for high-efficiency dye-sensitized solar cells. J. Am. Chem. Soc. 132, 16714–16724 (2010).
Hattori, S., Wada, Y., Yanagida, S. & Fukuzumi, S. Blue copper model complexes with distorted tetragonal geometry acting as effective electron-transfer mediators in dye-sensitized solar cells. J. Am. Chem. Soc. 127, 9648–9654 (2005).
Li, T. C. et al. Ni(III)/(IV) Bis(dicarbollide) as a fast, noncorrosive redox shuttle for dye-sensitized solar cells. J. Am. Chem. Soc. 132, 4580–4582 (2010).
Teng, C. et al. Two novel carbazole dyes for dye-sensitized solar cells with open-circuit voltages up to 1 V based on Br−/Br3− electrolytes. Org. Lett. 11, 5542–5545 (2009).
Snaith, H. J., Zakeeruddin, S. M., Wang, Q., Pechy, P. & Grätzel, M. Dye-sensitized solar cells incorporating a ‘liquid’ hole-transporting material. Nano Lett. 6, 2000–2003 (2006).
Wang, M. et al. An organic redox electrolyte to rival triiodide/iodide in dye-sensitized solar cells. Nat. Chem. 2, 385–389 (2010).
Tennakone, K. et al. A solid-state photovoltaic cell sensitized with a ruthenium bipyridyl complex. J. Phys. D 31, 1492–1496 (1998).
Yum, J. H., Chen, P., Grätzel, M. & Nazeeruddin, M. Recent developments in solid-state dye-sensitized solar cells. ChemSusChem 1, 699–707 (2008).
Pavlishchuk, V. V. & Addison, A. W. Conversion constants for redox potentials measured versus different reference electrodes in acetonitrile solutions at 25 °C. Inorg. Chim. Acta 298, 97–102 (2000).
Brown, K. N. et al. Electrochemistry of chlorinated ferrocenes: stability of chlorinated ferrocenium ions. Dalton Trans. 835–840 (1993).
Noviandri, I. et al. The decamethylferrocenium/decamethylferrocene redox couple: a superior redox standard to the ferrocenium/ferrocene redox couple for studying solvent effects on the thermodynamics of electron transfer. J. Phys. Chem. B 103, 6713–6722 (1999).
Hamann, T. W., Farha, O. K. & Hupp, J. T. Outer-sphere redox couples as shuttles in dye-sensitized solar cells. Performance enhancement based on photoelectrode modification via atomic layer deposition. J. Phys. Chem. C 112, 19756–19764 (2008).
Waita, S. M. et al. Electrochemical characterization of TiO2 blocking layers prepared by reactive DC magnetron sputtering. J. Electroanal. Chem. 637, 79–83 (2009).
Feldt, S. M., Cappel, U. B., Johansson, E. M. J., Boschloo, G. & Hagfeldt, A. Characterization of surface passivation by poly(methylsiloxane) for dye-sensitized solar cells employing the ferrocene redox couple. J. Phys. Chem. C 114, 10551–10558 (2010).
Zotti, G., Schiavon, G., Zecchin, S. & Favretto, D. Dioxygen-decomposition of ferrocenium molecules in acetonitrile: the nature of the electrode-fouling films during ferrocene electrochemistry. J. Electroanal. Chem. 456, 217–221 (1998).
Hurvois, J. P. & Moinet, C. Reactivity of ferrocenium cations with molecular oxygen in polar organic solvents: decomposition, redox reactions and stabilization. J. Organomet. Chem. 690, 1829–1839 (2005).
Schmidt-Mende, L. et al. Organic dye for highly efficient solid-state dye-sensitized solar cells. Adv. Mater. 17, 813–815 (2005).
Huang, S. Y., Schlichthorl, G., Nozik, A. J., Grätzel, M. & Frank, A. J. Charge recombination in dye-sensitized nanocrystalline TiO2 solar cells. J. Phys. Chem. B 101, 2576–2582 (1997).
Turbanov, K. Y. Interaction of ferricinium cation with pyridine. Zhurnal Obshchei Khimii 63, 1803–1809 (1993).
Mukherjee, L. M. Standard potential of the ferrocene–ferricinium electrode in pyridine. Evaluation of proton medium effect. J. Phys. Chem. B 76, 243–245 (1972).
Wang, Z.-S. et al. Thiophene-functionalized coumarin dye for efficient dye-sensitized solar cells: electron lifetime improved by coadsorption of deoxycholic acid. J. Phys. Chem. C 111, 7224–7230 (2007).
Nazeeruddin, M. K. et al. Combined experimental and DFT-TDDFT computational study of photoelectrochemical cell ruthenium sensitizers. J. Am. Chem. Soc. 127, 16835–16847 (2005).
Fisher, A. C., Peter, L. M., Ponomarev, E. A., Walker, A. B. & Wijayantha, K. G. U. Intensity dependence of the back reaction and transport of electrons in dye-sensitized nanocrystalline TiO2 solar cells. J. Phys. Chem. B 104, 949–958 (2000).
Duffy, N. W., Peter, L. M., Rajapakse, R. M. G. & Wijayantha, K. G. U. A novel charge extraction method for the study of electron transport and interfacial transfer in dye sensitised nanocrystalline solar cells. Electrochem. Commun. 2, 658–662 (2000).
Bessho, T. et al. New paradigm in molecular engineering of sensitizers for solar cell applications. J. Am. Chem. Soc. 131, 5930–5934 (2009).
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.
The authors declare no competing financial interests.
About this article
Cite this article
Daeneke, T., Kwon, TH., Holmes, A. et al. High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes. Nature Chem 3, 211–215 (2011). https://doi.org/10.1038/nchem.966
Electrochimica Acta (2021)
The Effects of Molecular Packing Behavior of Small-Molecule Acceptors in Ternary Organic Solar Cells
Applied Sciences (2021)
Effect of 1-Substituted 2-(Pyridin-2-yl)-1H-Benzo[d]imidazole Ligand-Coordinated Copper and Cobalt Complex Redox Electrolytes on Performance of Ru(II) Dye-Based Dye-Sensitized Solar Cells
Inorganic Chemistry (2021)
Chemical Science (2020)
Electrocatalytic oxidation of dopamine on the surface of ferrocene grafted hydroxyl terminated polybutadiene modified electrode