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.

  • Article
  • Published:

The effect of three-dimensional morphology on the efficiency of hybrid polymer solar cells

Nature Materials volume 8, pages 818–824 (2009)Cite this article

Abstract

The efficiency of polymer solar cells critically depends on the intimacy of mixing of the donor and acceptor semiconductors used in these devices to create charges and on the presence of unhindered percolation pathways in the individual components to transport holes and electrons. The visualization of these bulk heterojunction morphologies in three dimensions has been challenging and has hampered progress in this area. Here, we spatially resolve the morphology of 2%-efficient hybrid solar cells consisting of poly(3-hexylthiophene) as the donor and ZnO as the acceptor in the nanometre range by electron tomography. The morphology is statistically analysed for spherical contact distance and percolation pathways. Together with solving the three-dimensional exciton-diffusion equation, a consistent and quantitative correlation between solar-cell performance, photophysical data and the three-dimensional morphology has been obtained for devices with different layer thicknesses that enables differentiating between generation and transport as limiting factors to performance.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Performance of P3HT/ZnO solar cells.
Figure 2: PIA spectra of P3HT/ZnO layers.
Figure 3: Electron tomography of P3HT/ZnO solar cells.
Figure 4: Statistical analysis of the 3D morphology.
Figure 5: Exciton quenching efficiency cross-sections in P3HT/ZnO bulk heterojunctions.

Similar content being viewed by others

References

  1. Thompson, B. C. & Fréchet, J. M. J. Polymer-fullerene composite solar cells. Angew. Chem. Int. Ed. 47, 58–77 (2008).

    Article  CAS  Google Scholar 

  2. Park, S. H. et al. Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nature Photon. 3, 297–303 (2009).

    Article  CAS  Google Scholar 

  3. Liang, Y. et al. Highly efficient solar cell polymers developed via fine-tuning of structural and electronic properties. J. Am. Chem. Soc. 131, 7792–7799 (2009).

    Article  CAS  Google Scholar 

  4. Huynh, W. U., Dittmer, J. J. & Alivisatos, A. P. Hybrid nanorod-polymer solar cells. Science 295, 2425–2427 (2002).

    Article  CAS  Google Scholar 

  5. Wang, P. et al. Photoinduced charge transfer and efficient solar energy conversion in a blend of a red polyfluorene copolymer with CdSe nanoparticles. NanoLett. 6, 1789–1793 (2006).

    Article  CAS  Google Scholar 

  6. Kwong, C. Y., Djurisic, A. B., Chui, P. C., Cheng, K. W. & Chan, W. K. Influence of solvent on film morphology and device performance of poly(3-hexylthiophene): TiO2 nanocomposite solar cells. Chem. Phys. Lett. 384, 372–375 (2004).

    Article  CAS  Google Scholar 

  7. Kuo, C. Y., Tang, W. C., Gau, C., Guo, T. F. & Jeng, D. Z. Ordered bulk heterojunction solar cells with vertically aligned TiO2 nanorods embedded in a conjugated polymer. Appl. Phys. Lett. 93, 033307 (2008).

    Article  Google Scholar 

  8. Beek, W. J. E., Wienk, M. M. & Janssen, R. A. J. Efficient hybrid solar cells from zinc oxide and a conjugated polymer. Adv. Mater. 16, 1009–1013 (2004).

    Article  CAS  Google Scholar 

  9. Beek, W. J. E., Wienk, M. M. & Janssen, R. A. J. Hybrid solar cells from regioregular polythiophene and ZnO nanoparticles. Adv. Funct. Mater. 16, 1112–1116 (2006).

    Article  CAS  Google Scholar 

  10. Olson, D. C., Shaheen, S. E., Collins, R. T. & Ginley, D. S. Effect of polymer processing on the performance of poly(3-hexylthiophene)/ZnO nanorod photovoltaic devices. J. Phys. Chem. C 111, 16640–16645 (2007).

    Article  CAS  Google Scholar 

  11. Wang, H. et al. Titania bicontinuous network structures for solar cell applications. Appl. Phys. Lett. 87, 023507 (2005).

    Article  Google Scholar 

  12. Ravirajan, P. et al. Hybrid polymer/zinc oxide photovoltaic devices with vertically oriented ZnO nanorods and an amphiphilic molecular interface layer. J. Phys. Chem. B 110, 7635–7639 (2006).

    Article  CAS  Google Scholar 

  13. Zhu, R., Jiang, C.-Y. & Ramakrishna, S. Highly efficient nanoporous TiO2-polythiophene hybrid solar cells based on interfacial modification using a metal-free organic dye. Adv. Mater. 21, 994–1000 (2009).

    Article  CAS  Google Scholar 

  14. van Hal, P. A. et al. Photoinduced electron transfer and photovoltaic response of a MDMO-PPV: TiO2 bulk-heterojunction. Adv. Mater. 15, 118–121 (2003).

    Article  CAS  Google Scholar 

  15. Beek, W. J. E., Slooff, L. H., Kroon, J. M., Wienk, M. M. & Janssen, R. A. J. Hybrid solar cells using a zinc oxide precursor and a conjugated polymer. Adv. Funct. Mater. 15, 1703–1708 (2005).

    Article  CAS  Google Scholar 

  16. Moet, D. J. D., Koster, L. J. A., de Boer, B. & Blom, P. W. M. Hybrid polymer solar cells from highly reactive diethylzinc: MDMO-PPV versus P3HT. Chem. Mater. 19, 5856–5861 (2007).

    Article  CAS  Google Scholar 

  17. Schilinsky, P., Waldauf, C. & Brabec, C. J. Recombination and loss analysis in polythiophene based bulk heterojunction photodetectors. Appl. Phys. Lett. 81, 3885–3887 (2002).

    Article  CAS  Google Scholar 

  18. van Hal, P. A., Christiaans, M. P. T., Wienk, M. M., Kroon, J. M. & Janssen, R. A. J. Photoinduced electron transfer from conjugated polymers to TiO2 . J. Phys. Chem. B 103, 4352–4359 (1999).

    Article  CAS  Google Scholar 

  19. Shim, M. & Guyot-Sionnest, P. Organic-capped ZnO nanocrystals: Synthesis and n-type character. J. Am. Chem. Soc. 123, 11651–11654 (2001).

    Article  CAS  Google Scholar 

  20. Spano, F. C. Modeling disorder in polymer aggregates: The optical spectroscopy of regioregular poly(3-hexylthiophene) thin films. J. Chem. Phys. 122, 234701 (2005).

    Article  Google Scholar 

  21. Chang, J.-F. et al. Molecular-weight dependence of interchain polaron delocalization and exciton bandwidth in high-mobility conjugated polymers. Phys. Rev. B. 74, 115318 (2006).

    Article  Google Scholar 

  22. van Duren, J. K. J. et al. Relating the morphology of poly(p-phenylene vinylene)/methanofullerene blends to solar-cell performance. Adv. Funct. Mater. 14, 425–434 (2004).

    Article  CAS  Google Scholar 

  23. Yang, X., van Duren, J. K. J., Janssen, R. A. J., Michels, M. A. J. & Loos, J. Morphology and thermal stability of the active layer in poly(p-phenylenevinylene)/ methanofullerene plastic photovoltaic devices. Macromolecules 37, 2151–2158 (2004).

    Article  CAS  Google Scholar 

  24. Jinnai, H., Nishikawa, Y., Ikehara, T & Nishi, T. Emerging technologies for the 3D analysis of polymer structures. Adv. Polym. Sci. 170, 115–167 (2004).

    CAS  Google Scholar 

  25. Shaw, P. E., Ruseckas, A. & Samuel, I. D. W. Exciton diffusion measurements in poly(3-hexylthiophene). Adv. Mater. 20, 3516–3520 (2008).

    Article  CAS  Google Scholar 

  26. Piris, J. et al. The locus of free charge-carrier generation in solution-cast Zn1–xMgxO/poly(3-hexylthiophene) bilayers for photovoltaic applications. Adv. Funct. Mater. 17, 3849–3857 (2007).

    Article  CAS  Google Scholar 

  27. Becker, H., Burns, S. E. & Friend, R. H. Effect of metal films on the photoluminescence and electroluminescence of conjugated polymers. Phys. Rev. B. 56, 1893–1905 (1997).

    Article  CAS  Google Scholar 

  28. Yim, K.-H., Friend, R. H. & Kim, J. S. Anisotropic optical properties in electroluminescent conjugated polymers based on grazing angle photoluminescence measurements. J. Chem. Phys. 124, 184706 (2006).

    Article  Google Scholar 

  29. Markov, D. E. & Blom, P. W. M. Migration-assisted energy transfer at conjugated polymer/metal interfaces. Phys. Rev. B. 72, 161401(R) (2005).

    Article  Google Scholar 

Download references

Acknowledgements

The authors gratefully acknowledge D. Veldman for assistance with the PIA measurements and N. Lousberg for preparing a cross-section of a complete device by FIB processing. The research was supported by a TOP grant of the Chemical Sciences (CW) division of the Netherlands Organization for Scientific Research (NWO) and is part of the Joint Solar Programme (JSP). The JSP is co-financed by the Foundation for Fundamental Research on Matter (FOM), Chemical Sciences of NWO and the Foundation Shell Research. This work was further supported by the Deutsche Forschungsgemeinschaft under Priority Programme 1355 ‘Elementary Processes of Organic Photovoltaics’, Senter/Novem in the EOS project Zomer (EOSLT03026) and is part of the research program of the Dutch Polymer Institute (DPI, project 524).

Author information

Authors and Affiliations

  1. Molecular Materials and Nanosystems, Eindhoven University of Technology, 5600 MB Eindhoven, PO Box 513, The Netherlands

    Stefan D. Oosterhout, Martijn M. Wienk, L. Jan Anton Koster, Jan Gilot & René A. J. Janssen

  2. Laboratory of Materials and Interface Chemistry and Soft Matter Cryo-TEM Research Unit, Eindhoven University of Technology, 5600 MB Eindhoven, PO Box 513, The Netherlands

    Svetlana S. van Bavel & Joachim Loos

  3. Dutch Polymer Institute, 5600 AX Eindhoven, PO Box 902, The Netherlands

    Svetlana S. van Bavel

  4. Institute for Stochastics, Ulm University, 89069 Ulm, Germany

    Ralf Thiedmann & Volker Schmidt

Authors
  1. Stefan D. Oosterhout
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Martijn M. Wienk
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Svetlana S. van Bavel
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Ralf Thiedmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. L. Jan Anton Koster
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Jan Gilot
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Joachim Loos
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Volker Schmidt
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. René A. J. Janssen
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

S.O. made and characterized the devices, S.v.B. did the TEM measurements. R.T. carried out the statistical analysis. L.J.A.K. carried out the exciton diffusion calculations. J.G. did the optical modelling. M.W., J.L., V.S. and R.J. planned the research and supervised it. The article was written by S.O. and M.W.

Corresponding author

Correspondence to René A. J. Janssen.

Supplementary information

Supplementary Information

Supplementary Information (PDF 534 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Oosterhout, S., Wienk, M., van Bavel, S. et al. The effect of three-dimensional morphology on the efficiency of hybrid polymer solar cells. Nature Mater 8, 818–824 (2009). https://doi.org/10.1038/nmat2533

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat2533

This article is cited by

Search

Advanced 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