Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Bifacial dye-sensitized solar cells based on an ionic liquid electrolyte

Abstract

Solar energy is a promising solution to global energy-related problems because it is clean, inexhaustible and readily available. However, the deployment of conventional photovoltaic cells based on silicon is still limited by cost, so alternative, more cost-effective approaches are sought. Here we report a bifacial dye-sensitized solar cell structure that provides high photo-energy conversion efficiency (6%) for incident light striking its front or rear surfaces. The design comprises a highly stable ruthenium dye (Z907Na) in combination with an ionic-liquid electrolyte and a porous TiO2 layer. The inclusion of a SiO2 layer between the electrodes to prevent generation of unwanted back current and optimization of the thickness of the TiO2 layer are responsible for the enhanced performance.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Design of the bifacial DSC.
Figure 2: Relationship between the photovoltaic characteristics of bifacial DSCs with TiO2/SiO2 (3 µm thick) porous electrodes and the thickness of the porous TiO2 electrodes.
Figure 3: Experimental results of photovoltaic characteristics of DSCs with a porous TiO2 (16 µm thick) layer.
Figure 4: Electrical characteristics of the bifacial DSC.

References

  1. Mori, H. Radiation energy transducing device. US patent 3,278,811 (1966).

  2. Hübner, A., Aberle, A. G. & Hezel, R. Cost-effective bifacial silicon solar cells with 19% front and 18% rear efficiency. Conf. Proc. 25th PVSC, 13–17 May 1996, 489–492 (IEEE, Washington, DC).

  3. Hübner, A., Aberle, A. G. & Hezel, R. Novel cost-effective bifacial silicon solar cells with 19.4% front and 18.1% rear efficiency. Appl. Phys. Lett. 70, 1008–1010 (1997).

    ADS  Article  Google Scholar 

  4. Uematsu, T. et al. Development of bifacial PV cells for new applications of flat-plate modules. Solar Energy Mater. Solar Cells 75, 557–566 (2003).

    Article  Google Scholar 

  5. Khrypunov, G. et al. Recent development in evaporated CdTe solar cells. Solar Energy Mater. Solar Cells 90, 664–677 (2006).

    Article  Google Scholar 

  6. Rostan, P. J. et al. Formation of transparent and ohmic ZnO:Al/MoSe2 contacts for bifacial Cu(In,Ga)Se2 solar cells and tandem structures. Thin Solid Films 480–481, 67–70 (2005).

    ADS  Article  Google Scholar 

  7. Nakada, T. et al. Novel device structure for Cu(In,Ga)Se2 thin film solar cells using transparent conducting oxide back and front contacts. Solar Energy 77, 739–747 (2004).

    ADS  Article  Google Scholar 

  8. Schermer, J. J. et al. Photon confinement in high-efficiency, thin-film III–V solar cells obtained by epitaxial lift-off. Thin Solid Films 511–512, 645–653 (2006).

    ADS  Article  Google Scholar 

  9. O'Regan, B. & Grätzel, M. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 353, 737–739 (1991).

    ADS  Article  Google Scholar 

  10. Grätzel, M. Photoelectrochemical cells. Nature 414, 338–344 (2001).

    ADS  Article  Google Scholar 

  11. Smestad, G., Bignozzi, C. & Arazzi, R. Testing of dye-sensitized solar cells I: Experimental photocurrent output and conversion efficiencies. Solar Energy Mater. Solar Cells 32, 259–272 (1994).

    Article  Google Scholar 

  12. Tsubomura, H., Matsumura, M., Noyamaura, Y. & Amamiya, T. Dye sensitized zinc oxide: Aqueous electrolyte: Platinum photocell. Nature 261, 402–403 (1976).

    ADS  Article  Google Scholar 

  13. Matsumura, M. PhD thesis, Osaka University, Japan (1979).

  14. Nazeeruddin, Md. K. et al. Engineering of efficient panchromatic sensitizers for nanocrystalline TiO2-based solar cells. J. Am. Chem. Soc. 123, 1613–1624 (2001).

    Article  Google Scholar 

  15. Chiba, Y. et al. Dye-sensitized solar cells with conversion efficiency of 11.1%. Jpn J. Appl. Phys. 45, L638–L640 (2006).

    Article  Google Scholar 

  16. Wang, Z. S., Yamaguchi, T., Sugihara, H. & Arakawa, H. Significant efficiency improvement of the black dye-sensitized solar cell through protonation of TiO2 films. Langmuir 21, 4272–4276 (2005).

    Article  Google Scholar 

  17. Kuang, D. et al. Stable, high-efficiency ionic-liquid-based mesoscopic dye-sensitized solar cells. Small 3, 2094–2102 (2007).

    Article  Google Scholar 

  18. Ionic Liquids IIIA. Fundamentals, Progress, Challenges and Opportunities: Properties and Structure (eds Rogers, R. D. & Seddon K. R.) (ACS Symposium Series, 2005).

    Google Scholar 

  19. Kang, M. G. et al. A 4.2% efficient flexible dye-sensitized TiO2 solar cell using stainless steel substrate. Solar Energy Mater. Solar Cells 90, 574–581 (2006).

    ADS  Article  Google Scholar 

  20. Ito, S. et al. High-efficiency (7.2%) flexible dye-sensitized solar cells with Ti-metal substrate for nanocrystalline-TiO2 photoanode. Chem. Commun. 4004–4006 (2006).

  21. Mohmeyer, N. et al. An efficient organogelator for ionic liquids to prepare stable quasi-solid-state dye-sensitized solar cells. J. Mater. Chem. 16, 2978–2983 (2006).

    Article  Google Scholar 

  22. Kuang, D. et al. High molar extinction coefficient heteroleptic ruthenium complexes for thin film dye-sensitized solar cells. J. Am. Chem. Soc. 128, 4146–4154 (2006).

    Article  Google Scholar 

  23. Kubo, W. et al. Photocurrent-determining processes in quasi-solid-state dye-sensitized solar cells using ionic gel electrolytes. J. Phys. Chem. B 107, 4374–4381 (2003).

    Article  Google Scholar 

  24. Ito, S. et al. High-efficiency organic-dye-sensitized solar cells controlled by nanocrystalline-TiO2 electrode thickness. Adv. Mater. 18, 1202–1205 (2006).

    Article  Google Scholar 

  25. Würfel, U., Wagner, J. & Hinsch, A. Spatial electron distribution and its origin in the nanoporous TiO2 network of a dye solar cell. J. Phys. Chem. B 109, 20444–20448 (2005).

    Article  Google Scholar 

  26. Fabregat-Santiago, F. et al. Influence of electrolyte in transport and recombination in dye-sensitized solar cells studied by impedance spectroscopy. Solar Energy Mater. Solar Cells 87, 117–131 (2005).

    Article  Google Scholar 

  27. Usui, H., Matsui, H., Tanabe, N. & Yanagida, S. Improved dye-sensitized solar cells using ionic nanocomposite gel electrolytes. J. Photochem. Photobiol. A 164, 97–101 (2004).

    Article  Google Scholar 

  28. Berginc, M. et al. Ionic liquid-based electrolyte solidified with SiO2 nanoparticles for dye-sensitized solar cells. Thin Solid Films 516, 4645–4650 (2008).

    ADS  Article  Google Scholar 

  29. Kern, R. et al. Modeling and interpretation of electrical impedance spectra of dye solar cells operated under open-circuit conditions. Electrochim. Acta 47, 4213–4225 (2002).

    Article  Google Scholar 

  30. Wang, P. et al. Charge separation and efficient light energy conversion in sensitized mesoscopic solar cells based on binary ionic liquids. J. Am. Chem. Soc. 127, 6850–6856 (2005).

    Article  Google Scholar 

  31. Burnside, S. D. et al. Self-organization of TiO2 nanoparticles in thin films. Chem. Mater. 10, 2419–2425 (1998).

    Article  Google Scholar 

  32. Ito, S. et al. Fabrication of thin film dye sensitized solar cells with solar to electric power conversion efficiency over 10%. Thin Solid Films 516, 4613–4619 (2008).

    ADS  Article  Google Scholar 

  33. Ito, S. et al. Calibration of solar simulator for evaluation of dye-sensitized solar cells. Solar Energy Mater. Solar Cells 82, 421–429 (2004).

    Article  Google Scholar 

  34. Ito, S. et al. Photovoltaic characterization of dye-sensitized solar cells: Effect of device masking on conversion efficiency. Progr. Photovol. 14, 589–601 (2006).

    Article  Google Scholar 

Download references

Acknowledgements

This work was supported by a grant from the Swiss Federal Energy Office (OFEN). The UV-curing glue and the SiO2 slurry (d = 600 nm) were provided by Three Bond (K. Kishi) and CCIC (T. Mizuno and T. Koyanagi), respectively.

Author information

Authors and Affiliations

Authors

Contributions

S.I. fabricated the TiO2 electrodes, TiO2/SiO2 electrodes and platinum electrodes, assembled cells, and performed the measurements for Figs 24. S.Z. synthesized the ruthenium dye (Z907) and the ionic liquid. P.C. synthesized the TiO2 nanoparticles. P.L. provided guidance on how to assemble the cells and equipment control. D.K. provided the details of the ionic–ionic liquid information. M.G. provided technical advice.

Corresponding author

Correspondence to Seigo Ito.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ito, S., Zakeeruddin, S., Comte, P. et al. Bifacial dye-sensitized solar cells based on an ionic liquid electrolyte. Nature Photon 2, 693–698 (2008). https://doi.org/10.1038/nphoton.2008.224

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphoton.2008.224

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing