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Lead-free solid-state organic–inorganic halide perovskite solar cells


Lead-free solution-processed solid-state photovoltaic devices based on methylammonium tin iodide (CH3NH3SnI3) perovskite semiconductor as the light harvester are reported. Featuring an optical bandgap of 1.3 eV, the CH3NH3SnI3 perovskite material can be incorporated into devices with the organic hole-transport layer spiro-OMeTAD and show an absorption onset at 950 nm, which is significantly redshifted compared with the benchmark CH3NH3PbI3 counterpart (1.55 eV). Bandgap engineering was implemented by chemical substitution in the form of CH3NH3SnI3–xBrx solid solutions, which can be controllably tuned to cover much of the visible spectrum, thus enabling the realization of lead-free solar cells with an initial power conversion efficiency of 5.73% under simulated full sunlight. Further efficiency enhancements are expected following optimization and a better fundamental understanding of the internal electron dynamics and corresponding interfacial engineering. The reported CH3NH3SnI3–xBrx perovskite solar cells represent a step towards the realization of low-cost, environmentally friendly solid-state solar cells.

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Figure 1: Crystal structure, XRD pattern, optical absorption and photoluminescence spectra, conductivity and Seebeck coefficient of CH3NH3SnI3 perovskite.
Figure 2: Representative cross-sectional SEM view of a completed photovoltaic device with CH3NH3SnI3 perovskite.
Figure 3: Photovoltaic and IPCE characteristics for devices with CH3NH3SnI3−xBrx perovskites.
Figure 4: XRD patterns, absorption spectra and schematic energy-level diagram of CH3NH3SnI3−xBrx compounds.


  1. Bisquert, J. Photovoltaics: the two sides of solar energy. Nature Photon. 2, 648–649 (2008).

    Article  ADS  Google Scholar 

  2. Chung, I., Lee, B., He, J., Chang, R. P. H. & Kanatzidis, M. G. All-solid-state dye-sensitized solar cells with high efficiency. Nature 485, 486–489 (2012).

    Article  ADS  Google Scholar 

  3. Kojima, A., Teshima, K., Shirai, Y. & Miyasaka, T. Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. J. Am. Chem. Soc. 131, 6050–6051 (2009).

    Article  Google Scholar 

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

    Article  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 10.1038/srep00591(2012).

    Article  Google Scholar 

  6. Heo, J. H. et al. Efficient inorganic–organic hybrid heterojunction solar cells containing perovskite compound and polymeric hole conductors. Nature Photon. 7, 487–492 (2013).

    Article  ADS  Google Scholar 

  7. 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 

  8. 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 

  9. Kim, H.-S. et al. High efficiency solid-state sensitized solar cell-based on submicrometer rutile TiO2 nanorod and CH3NH3PbI3 perovskite sensitizer. Nano Lett. 13, 2412–2417 (2013).

    Article  ADS  Google Scholar 

  10. Abrusci, A. et al. High-performance perovskite–polymer hybrid solar cells via electronic coupling with fullerene monolayers. Nano Lett. 13, 3124–3128 (2013).

    Article  ADS  Google Scholar 

  11. Edri, E., Kirmayer, S., Cahen, D. & Hodes, G. High open-circuit voltage solar cells based on organic–inorganic lead bromide perovskite. J. Phys. Chem. Lett. 4, 897–902 (2013).

    Article  Google Scholar 

  12. 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 

  13. Ball, J. M., Lee, M. M., Hey, A. & Snaith, H. J. Low-temperature processed meso-superstructured to thin-film perovskite solar cells. Energy Environ. Sci. 6, 1739–1743 (2013).

    Article  Google Scholar 

  14. Laban, W. A. & Etgar, L. Depleted hole conductor-free lead halide iodide heterojunction solar cells. Energy Environ. Sci. 6, 3249–3253 (2013).

    Article  Google Scholar 

  15. Borriello, I., Cantele, G. & Ninno, D. Ab initio investigation of hybrid organic–inorganic perovskites based on tin halides. Phys. Rev. B 77, 235214 (2008).

    Article  ADS  Google Scholar 

  16. Mitzi, D. B. Synthesis, structure, and properties of organic–inorganic perovskites and related materials. Prog. Inorg. Chem. 48, 1–121 10.1002/9780470166499.ch1(1999).

    Article  Google Scholar 

  17. Kagan, C. R., Mitzi, D. B. & Dimitrakopoulos, C. D. Organic–inorganic hybrid materials as semiconducting channels in thin-film field-effect transistors. Science 286, 945–947 (1999).

    Article  Google Scholar 

  18. 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 

  19. Snaith, H. J. Perovskites: the emergence of a new era for low-cost, high-efficiency solar cells. J. Phys. Chem. Lett. 4, 3623–3630 (2013).

    Article  Google Scholar 

  20. Park, N.-G. Organometal perovskite light absorbers toward a 20% efficiency low-cost solid-state mesoscopic solar cell. J. Phys. Chem. Lett. 4, 2423–2429 (2013).

    Article  Google Scholar 

  21. Hodes, G. Perovskite-based solar cells. Science 342, 317–318 (2013).

    Article  ADS  Google Scholar 

  22. Bisquert, J. The swift surge of perovskite photovoltaics. J. Phys. Chem. Lett. 4, 2597–2598 (2013).

    Article  Google Scholar 

  23. 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 

  24. 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 

  25. 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 

  26. Umari, P., Mosconi, E. & de Angelis, F. Relativistic solar cells. Preprint at (2013).

  27. Gate, L. F. Comparison of the photon diffusion model and Kubelka–Munk equation with the exact solution of the radiative transport equation. Appl. Opt. 13, 236–238 (1974).

    Article  ADS  Google Scholar 

  28. Rein, S. Lifetime Spectroscopy: A Method of Defect Characterization in Silicon for Photovoltaic Applications (Springer, 2004).

    Google Scholar 

  29. Takahashi, Y., Hasegawa, H., Takahashi, Y. & Inabe, T. Hall mobility in tin iodide perovskite CH3NH3SnI3: evidence for a doped semiconductor. J. Solid State Chem. 205, 39–43 (2013).

    Article  ADS  Google Scholar 

  30. 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).

    Article  ADS  Google Scholar 

  31. Bach, U. et al. Solid-state dye-sensitized mesoporous TiO2 solar cells with high photon-to-electron conversion efficiencies. Nature 395, 583–585 (1998).

    Article  ADS  Google Scholar 

  32. 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 10.1021/nl3007165(2013).

    Article  ADS  Google Scholar 

  33. Kim, H.-S. et al. Mechanism of carrier accumulation in perovskite thin-absorber solar cells. Nature Commun. 4, 2242 10.1038/ncomms3242(2013).

    Article  ADS  Google Scholar 

  34. Docampo, P. & Snaith, H. J. Obviating the requirement for oxygen in SnO2-based solid-state dye-sensitized solar cells. Nanotechnology 22, 225403 (2011).

    Article  ADS  Google Scholar 

  35. Mitzi, D. B., Dimitrakopoulos, C. D. & Kosbar, L. L. Structurally tailored organic–inorganic perovskites: optical properties and solution-processed channel materials for thin-film transistors. Chem. Mater. 13, 3728–3740 (2001).

    Article  Google Scholar 

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The authors thank T. Marks for use of the solar simulator and IPCE measurement system. Electron microscopy and elemental analysis were carried out at the Electron Probe Instrumentation Center (EPIC) at Northwestern University. This research was supported as part of the ANSER Center, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences (award no. DE-SC0001059) and ISEN at Northwestern University.

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M.G.K. conceived the experiments and directed the study. F.H. and C.C.S. carried out the material synthesis, device fabrication and performance measurements. D.H.C. prepared the TiO2 blocking layer for the electrodes. R.P.H.C. contributed to the revision of the manuscript. All authors discussed the results and commented on the manuscript.

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Correspondence to Mercouri G. Kanatzidis.

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The authors declare no competing financial interests.

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Hao, F., Stoumpos, C., Cao, D. et al. Lead-free solid-state organic–inorganic halide perovskite solar cells. Nature Photon 8, 489–494 (2014).

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