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Reduction of lead leakage from damaged lead halide perovskite solar modules using self-healing polymer-based encapsulation


In recent years, the major factors that determine commercialization of perovskite photovoltaic technology have been shifting from solar cell performance to stability, reproducibility, device upscaling and the prevention of lead (Pb) leakage from the module over the device service life. Here we simulate a realistic scenario in which perovskite modules with different encapsulation methods are mechanically damaged by a hail impact (modified FM 44787 standard) and quantitatively measure the Pb leakage rates under a variety of weather conditions. We demonstrate that the encapsulation method based on an epoxy resin reduces the Pb leakage rate by a factor of 375 compared with the encapsulation method based on a glass cover with an ultraviolet-cured resin at the module edges. The greater Pb leakage reduction of the epoxy resin encapsulation is associated with its optimal self-healing characteristics under the operating conditions and with its increased mechanical strength. These findings strongly suggest that perovskite photovoltaic products can be deployed with minimal Pb leakage if appropriate encapsulation is employed.

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The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.


  1. 1.

    Best Research Cell Efficiencies (NREL, 2019);

  2. 2.

    Green, M. A. et al. Solar cell efficiency tables (version 53). Prog. Photovolt. Res. Appl. 27, 3–12 (2019).

  3. 3.

    Correa-Baena, J. et al. Promises and challenges of perovskite solar cells. Science 358, 739–744 (2017).

  4. 4.

    Park, N.-G., Grätzel, M., Miyasaka, T., Zhu, K. & Emery, K. Towards stable and commercially available perovskite solar cells. Nat. Energy 1, 16152 (2016).

  5. 5.

    Rong, Y. et al. Challenges for commercializing perovskite solar cells. Science 361, eaat8235 (2018).

  6. 6.

    Christians, J. A. et al. Tailored interfaces of unencapsulated perovskite solar cells for >1,000 hour operational stability. Nat. Energy 3, 68–74 (2018).

  7. 7.

    Ono, L. K., Qi, Y. B. & Liu, S. Z. Progress toward stable lead halide perovskite solar cells. Joule 2, 1961–1990 (2018).

  8. 8.

    Park, N., Huang, J. & Qi, Y. B. Themed issue on perovskite solar cells: research on metal halide perovskite solar cells towards deeper understanding, upscalable fabrication, long-term stability and Pb-free alternatives. Sustain. Energy Fuels 2, 2378–2380 (2018).

  9. 9.

    Juarez-Perez, E. J. et al. Photo-, thermal-decomposition in methylammonium halide lead perovskites and inferred design principles to increase photovoltaic device stability. J. Mater. Chem. A 6, 9604–9612 (2018).

  10. 10.

    Wang, S., Jiang, Y., Juarez-Perez, E. J., Ono, L. K. & Qi, Y. B. Accelerated degradation of methylammonium lead iodide perovskites induced by exposure to iodine vapour. Nat. Energy 2, 16195 (2016).

  11. 11.

    Juarez-Perez, E. J., Hawash, Z., Raga, S. R., Ono, L. K. & Qi, Y. B. Thermal degradation of CH3NH3PbI3 perovskite into NH3 and CH3I gases observed by coupled thermogravimetry–mass spectrometry analysis. Energy Environ. Sci. 9, 3406–3410 (2016).

  12. 12.

    Rajagopal, A., Yao, K. & Jen, A. K. Toward perovskite solar cell commercialization: a perspective and research roadmap based on interfacial engineering. Adv. Mater. 30, 1800455 (2018).

  13. 13.

    Ju, M. et al. Toward eco-friendly and stable perovskite materials for photovoltaics. Joule 2, 1231–1241 (2018).

  14. 14.

    Abate, A. Perovskite solar cells go lead free. Joule 1, 659–664 (2018).

  15. 15.

    Shi, Z. J. et al. Lead-free organic-inorganic hybrid perovskites for photovoltaic applications: recent advances and perspectives. Adv. Mater. 26, 1605005 (2017).

  16. 16.

    Jiang, S., Wang, K., Zhang, H., Ding, Y. & Yu, Q. Encapsulation of PV modules using ethylene vinyl acetate copolymer as the encapsulant. Macromol. React. Eng. 9, 522–529 (2015).

  17. 17.

    Manufacture of a CIGS Solar Module (Soltecture, 2018);

  18. 18.

    Hirata, M. K., Freitas, J. N., Santos, T. E. A., Mammana, V. P. & Nogueira, A. F. Assembly considerations for dye-sensitized solar modules with polymer gel electrolyte. Ind. Eng. Chem. Res. 55, 10278–10285 (2016).

  19. 19.

    Wang, Z. et al. Efficient and air-stable mixed-cation lead mixed-halide perovskite solar cells with n-doped organic electron extraction layers. Adv. Mater. 29, 1604186 (2017).

  20. 20.

    Cheacharoen, R. et al. Design and understanding of encapsulated perovskite solar cells to withstand temperature cycling. Energy Environ. Sci. 11, 144–150 (2018).

  21. 21.

    Jiang, Y. et al. Combination of hybrid CVD and cation exchange for upscaling Cs-substituted mixed cation perovskite solar cells with high efficiency and stability. Adv. Funct. Mater. 28, 1703835 (2018).

  22. 22.

    Kalista, S. J. Jr Self-healing of Thermoplastic Poly(ethylene-co-methacrylic Acid) Copolymers Following Projectile Puncture. Masters Thesis, Virginia Tech (2003).

  23. 23.

    Lertngim, A. et al. Preparation of Surlyn films reinforced with cellulose nanofibres and feasibility of applying the transparent composite films for organic photovoltaic encapsulation. R. Soc. Open Sci. 4, 170792 (2017).

  24. 24.

    Approval Standard for Rigid Photovoltaic Modules (FM 44787) (FM Approvals, 2018);

  25. 25.

    Solar Resource Information (NREL, 2018);

  26. 26.

    Hailegnaw, B., Kirmayer, S., Edri, E., Hodes, G. & Cahen, D. Rain on methylammonium lead iodide based perovskites: possible environmental effects of perovskite solar cells. J. Phys. Chem. Lett. 6, 1543–1547 (2015).

  27. 27.

    Mathiak, G. et al. PV module damages caused by hail impact field experience and lab tests. In 31st European Photovoltaic Solar Energy Conference and Exhibition 1915–1919 (EU PVCSE, 2015).

  28. 28.

    Leyden, M. R., Jiang, Y. & Qi, Y. B. Chemical vapor deposition grown formamidinium perovskite solar modules with high steady state power and thermal stability. J. Mater. Chem. A 4, 13125–13132 (2016).

  29. 29.

    Pantic, L. S. et al. The assessment of different models to predict solar module temperature, output power and efficiency for Nis, Serbia. Energy 109, 38–48 (2016).

  30. 30.

    Espinosa, N., Zimmermann, Y., Benatto, G. A. R., Lenz, M. & Krebs, F. C. Outdoor fate and environmental impact of polymer solar cells through leaching and emission to rainwater and soil. Energy Environ. Sci. 9, 1674–1680 (2016).

  31. 31.

    Serrano-Lujan, L. et al. Tin- and lead-based perovskite solar cells under scrutiny: an environmental perspective. Adv. Energy Mater. 5, 1501119 (2015).

  32. 32.

    Hauck, M., Ligthart, T., Schaap, M., Boukris, E. & Brouwer, D. Environmental benefits of reduced electricity use exceed impacts from lead use for perovskite based tandem solar cell. Renew. Energy 111, 906–913 (2017).

  33. 33.

    Celik, I. et al. Life cycle assessment (LCA) of perovskite PV cells projected from lab to fab. Sol. Energy Mater. Sol. Cells 156, 157–169 (2016).

  34. 34.

    Celik, I., Song, Z., Phillips, A. B., Heben, M. J. & Apul, D. Life cycle analysis of metals in emerging photovoltaic (PV) technologies: a modeling approach to estimate use phase leaching. J. Clean. Prod. 186, 632–639 (2018).

  35. 35.

    Celik, I. et al. Environmental analysis of perovskites and other relevant solar cell technologies in a tandem configuration. Energy Environ. Sci. 10, 1874–1884 (2017).

  36. 36.

    Babayigit, A. et al. Assessing the toxicity of Pb- and Sn-based perovskite solar cells in model organism Danio rerio. Sci. Rep. 6, 18721 (2016).

  37. 37.

    Babayigit, A., Ethirajan, A., Muller, M. & Conings, B. Toxicity of organometal halide perovskite solar cells. Nat. Mater. 15, 247–251 (2016).

  38. 38.

    Lv, T. et al. Self-restoration of superhydrophobicity on shape memory polymer arrays with both crushed microstructure and damaged surface chemistry. Small 13, 1503402 (2017).

  39. 39.

    Holzhey, P. & Saliba, M. A full overview of international standards assessing the long-term stability of perovskite solar cells. J. Mater. Chem. A 6, 21794–21808 (2018).

  40. 40.

    Water in the Atmosphere (Met Office, 2007);

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This work was supported by funding from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University, the OIST R&D Cluster Research Program, the OIST Proof of Concept (POC) Program, and JSPS KAKENHI Grant no. JP18K05266. We thank Y. Iinuma (the technician at OIST) for the ICP–MS measurements.

Author information

Y.Q. conceived the idea, initiated and supervised the work. Y.J. and L.Q. designed the experiment, prepared the modules, tested the module breaking conditions and measured the Pb leakage. Y.J. performed the current density–voltage measurements and water CA measurements. L.Q. carried out the differential scanning calorimeter measurements. E.J.J.-P. did the thermogravimetric measurements. All the authors contributed to writing the paper.

Correspondence to Yabing Qi.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–14, Supplementary Tables 1–5, Supplementary Notes 1 and 2, and Supplementary references.

Reporting Summary

Supplementary Video 1

Mechanical strength of the ER polymers with different composition at 65 °C.

Supplementary Video 2

Mechanical strength of the ER polymers with different composition at 85 °C.

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Further reading

Fig. 1: Assessment of Pb leakage from damaged perovskite solar modules.
Fig. 2: Hail and weather tests on perovskite solar modules with different encapsulations.
Fig. 3: Pb concentration in the contaminated water.
Fig. 4: Self-healing properties of the ER encapsulant.
Fig. 5: Effect of four different weather conditions on Pb leakage with different encapsulation methods.