Skip to main content

Thank you for visiting 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.

Unravelling the mechanism of photoinduced charge transfer processes in lead iodide perovskite solar cells


Lead halide perovskites have recently been used as light absorbers in hybrid organic–inorganic solid-state solar cells, with efficiencies as high as 15% and open-circuit voltages of 1 V. However, a detailed explanation of the mechanisms of operation within this photovoltaic system is still lacking. Here, we investigate the photoinduced charge transfer processes at the surface of the perovskite using time-resolved techniques. Transient laser spectroscopy and microwave photoconductivity measurements were applied to TiO2 and Al2O3 mesoporous films impregnated with CH3NH3PbI3 perovskite and the organic hole-transporting material spiro-OMeTAD. We show that primary charge separation occurs at both junctions, with TiO2 and the hole-transporting material, simultaneously, with ultrafast electron and hole injection taking place from the photoexcited perovskite over similar timescales. Charge recombination is shown to be significantly slower on TiO2 than on Al2O3 films.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1
Figure 2: Time evolution of electron and hole populations in photoexcited CH3NH3PbI3 perovskite in various systems.
Figure 3: Transient microwave photoconductance measurements of the perovskite material deposited on various substrates.
Figure 4: Charge recombination dynamics obtained from nanosecond-laser flash photolysis of the various systems.


  1. Burschka, J. et al. Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature 499, 316–319 (2013).

    Article  ADS  Google Scholar 

  2. Heo, J. H. et al. Efficient inorganic–organic hybrid heterojunction solar cells containing perovskite compound and polymeric hole conductors. Nature Photon. 7, 486–491 (2013).

    Article  ADS  Google Scholar 

  3. Noh, J. H., Im, S. H., Heo, J. H., Mandal, T. N. & Seok, S. I. Chemical management for colorful, efficient, and stable inorganic–organic hybrid nanostructured solar cells. Nano Lett. 13, 1764–1769 (2013).

    Article  ADS  Google Scholar 

  4. Qiu, J. et al. All-solid-state hybrid solar cells based on a new organometal halide perovskite sensitizer and one-dimensional TiO2 nanowire arrays. Nanoscale 5, 3245–3248 (2013).

    Article  ADS  Google Scholar 

  5. Kim, H.-S. et al. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Sci. Rep. 2, 591 (2012).

    Article  Google Scholar 

  6. Lee, M. M., Teuscher, J., Miyasaka, T., Murakami, T. N. & Snaith, H. J. Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338, 643–647 (2012).

    Article  ADS  Google Scholar 

  7. Im, J.-H., Lee, C.-R., Lee, J.-W., Park, S.-W. & Park, N.-G. 6.5% efficient perovskite quantum-dot-sensitized solar cell. Nanoscale 3, 4088–4093 (2011).

    Article  ADS  Google Scholar 

  8. Papavassiliou, G. C. Three- and low-dimensional inorganic semiconductors. Prog. Solid State Chem. 25, 125–270 (1997).

    Article  Google Scholar 

  9. Ishihara, T. Optical properties of PbI-based perovskite structures. J. Lumin. 60, 269–274 (1994).

    Article  Google Scholar 

  10. Mitzi, D. B. Templating and structural engineering in organic–inorganic perovskites. J. Chem. Soc. Dalton Trans. 1–12 (2001).

  11. Stoumpos, C. C., Malliakas, C. D. & Kanatzidis, M. G. Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties. Inorg. Chem. 52, 9019–9038 (2013).

    Article  Google Scholar 

  12. Etgar, L. et al. Mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cells. J. Am. Chem. Soc. 134, 17396–17399 (2012).

    Article  Google Scholar 

  13. Bi, D., Yang, L., Boschloo, G., Hagfeldt, A. & Johansson, E. M. J. Effect of different hole transport materials on recombination in CH3NH3PbI3 perovskite-sensitized mesoscopic solar cells. J. Phys. Chem. Lett. 4, 1532–1536 (2013).

    Article  Google Scholar 

  14. Liu, M., Johnston, M. B. & Snaith, H. J. Efficient planar heterojunction perovskite solar cells by vapour deposition. Nature 501, 395–398 (2013).

    Article  ADS  Google Scholar 

  15. Snaith, H. J. et al. Charge collection and pore filling in solid-state dye-sensitized solar cells. Nanotechnology 19, 424003 (2008).

    Article  Google Scholar 

  16. Olson, C., Veldman, D., Bakker, K. & Lenzmann, F. Characterization of the pore filling of solid state dye sensitized solar cells with photoinduced absorption spectroscopy. Int. J. Photoenergy 2011, 513089 (2011).

    Article  Google Scholar 

  17. Rothenberger, G., Fitzmaurice, D. & Grätzel, M. Spectroscopy of conduction band electrons in transparent metal oxide semiconductor films: optical determination of the flatband potential of colloidal titanium dioxide films. J. Phys. Chem. 96, 5983–5986 (1992).

    Article  Google Scholar 

  18. Stranks, S. D. et al. Electron–hole diffusion lengths exceeding 1 micrometer in an organometal trihalide perovskite absorber. Science 342, 341–344 (2013).

    Article  ADS  Google Scholar 

  19. Xing, G. et al. Long-range balanced electron- and hole-transport lengths in organic–inorganic CH3NH3PbI3 . Science 342, 344–347 (2013).

    Article  ADS  Google Scholar 

  20. Friedrich, D. & Kunst, M. Analysis of charge carrier kinetics in nanoporous systems by time resolved photoconductance measurements. J. Phys. Chem. C 115, 16657–16663 (2011).

    Article  Google Scholar 

Download references


Financial support was provided by the Swiss National Science Foundation and the NCCR-MUST programme. M.G. and J.T. acknowledge the European Research Council (ERC) for an Advanced Research Grant (ARG no. 247404) funded under the ‘Mesolight’ project. A.M. and J.-E.M. thank J. Burschka, A. Dualeh, S. M. Zakeeruddin and C. Grätzel for discussions, P. Comte for the preparation of Al2O3 paste, P. Gao for the preparation of CH3NH3I, A. Devižis for help with near-infrared detection and A. Gasperini for atomic force microscopy measurements.

Author information

Authors and Affiliations



A.M. designed the experiments and prepared the samples. A.M. and J.T. carried out the laser experiments and analysed the data with J.-E.M. T.M. and D.F. designed the photoconductance experiments. D.F. performed the microwave experiments on the samples prepared by T.M. and analysed the data with the help of T.M., M.K. and R.vdK. A.M. prepared the manuscript with the help of J.T. and J.-E.M. J.-E.M. designed the femtosecond and nanosecond experimental spectroscopy tools, conceived the project and directed the work. All other authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Jacques-E. Moser.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Marchioro, A., Teuscher, J., Friedrich, D. et al. Unravelling the mechanism of photoinduced charge transfer processes in lead iodide perovskite solar cells. Nature Photon 8, 250–255 (2014).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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