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All-perovskite tandem solar cells with 24.2% certified efficiency and area over 1 cm2 using surface-anchoring zwitterionic antioxidant


Monolithic all-perovskite tandem solar cells offer an avenue to increase power conversion efficiency beyond the limits of single-junction cells. It is an important priority to unite efficiency, uniformity and stability, yet this has proven challenging because of high trap density and ready oxidation in narrow-bandgap mixed lead–tin perovskite subcells. Here we report simultaneous enhancements in the efficiency, uniformity and stability of narrow-bandgap subcells using strongly reductive surface-anchoring zwitterionic molecules. The zwitterionic antioxidant inhibits Sn2+ oxidation and passivates defects at the grain surfaces in mixed lead–tin perovskite films, enabling an efficiency of 21.7% (certified 20.7%) for single-junction solar cells. We further obtain a certified efficiency of 24.2% in 1-cm2-area all-perovskite tandem cells and in-lab power conversion efficiencies of 25.6% and 21.4% for 0.049 cm2 and 12 cm2 devices, respectively. The encapsulated tandem devices retain 88% of their initial performance following 500 hours of operation at a device temperature of 54–60 °C under one-sun illumination in ambient conditions.

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Fig. 1: Characterization of mixed Pb–Sn narrow-bandgap perovskite films with FSA.
Fig. 2: Charge dynamics and uniformity of Pb–Sn narrow-bandgap perovskite films with FSA.
Fig. 3: PV performance of mixed Pb–Sn narrow-bandgap solar cells.
Fig. 4: PV performance of monolithic all-perovskite tandem solar cells.
Fig. 5: Atmospheric and operating stability of all-perovskite tandem solar cells.

Data availability

All data generated or analysed during this study are included in the published article and its Supplementary Information and Source Data files. Source data are provided with this paper.


  1. Min, H. et al. Efficient, stable solar cells by using inherent bandgap of a-phase formamidinium lead iodide. Science 366, 749–753 (2019).

    Google Scholar 

  2. Jiang, Q. et al. Surface passivation of perovskite film for efficient solar cells. Nat. Photon. 13, 460–466 (2019).

    Google Scholar 

  3. Green, M. A. et al. Solar cell efficiency tables (version 55). Prog. Photovoltaics Res. Appl. 28, 3–15 (2020).

    Google Scholar 

  4. Eperon, G. E., Hörantner, M. T. & Snaith, H. J. Metal halide perovskite tandem and multiple-junction photovoltaics. Nat. Rev. Chem. 1, 0095 (2017).

    Google Scholar 

  5. Leijtens, T., Bush, K. A., Prasanna, R. & McGehee, M. D. Opportunities and challenges for tandem solar cells using metal halide perovskite semiconductors. Nat. Energy 3, 828–838 (2018).

    Google Scholar 

  6. Lin, R. et al. Monolithic all-perovskite tandem solar cells with 24.8% efficiency exploiting comproportionation to suppress Sn(ii) oxidation in precursor ink. Nat. Energy 4, 864–873 (2019).

    Google Scholar 

  7. Tong, J. et al. Carrier lifetimes of >1 μs in Sn-Pb perovskites enable efficient all-perovskite tandem solar cells. Science 364, 475–479 (2019).

    Google Scholar 

  8. Zhao, D. et al. Efficient two-terminal all-perovskite tandem solar cells enabled by high-quality low-bandgap absorber layers. Nat. Energy 3, 1093–1100 (2018).

    Google Scholar 

  9. Eperon, G. E. et al. Perovskite-perovskite tandem photovoltaics with optimized band gaps. Science 354, 861–865 (2016).

    Google Scholar 

  10. Palmstrom, A. F. et al. Enabling flexible all-perovskite tandem solar cells. Joule 3, 2193–2204 (2019).

    Google Scholar 

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

    Google Scholar 

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

    Google Scholar 

  13. Park, N.-G. & Zhu, K. Scalable fabrication and coating methods for perovskite solar cells and solar modules. Nat. Rev. Mater. 5, 333–350 (2020).

    Google Scholar 

  14. Werner, J. et al. Improving low-bandgap tin–lead perovskite solar cells via contact engineering and gas quench processing. ACS Energy Lett. 5, 1215–1223 (2020).

    Google Scholar 

  15. Zeng, L. et al. 2D-3D heterostructure enables scalable coating of efficient low-bandgap Sn–Pb mixed perovskite solar cells. Nano Energy 66, 104099 (2019).

    Google Scholar 

  16. Gu, S. et al. Tin and mixed lead–tin halide perovskite solar cells: progress and their application in tandem solar cells. Adv. Mater. 32, 1907392 (2020).

    Google Scholar 

  17. Ma, L. et al. Carrier diffusion lengths of over 500 nm in lead-free perovskite CH3NH3SnI3 films. J. Am. Chem. Soc. 138, 14750–14755 (2016).

    Google Scholar 

  18. Konstantakou, M. & Stergiopoulos, T. A critical review on tin halide perovskite solar cells. J. Mater. Chem. A 5, 11518–11549 (2017).

    Google Scholar 

  19. Lee, S. J. et al. Fabrication of efficient formamidinium tin iodide perovskite solar cells through SnF2–pyrazine complex. J. Am. Chem. Soc. 138, 3974–3977 (2016).

    Google Scholar 

  20. Tai, Q. et al. Antioxidant grain passivation for air-stable tin-based perovskite solar cells. Angew. Chem. Int. Ed. 58, 806–810 (2019).

    Google Scholar 

  21. Saidaminov, M. I. et al. Conventional solvent oxidizes Sn(II) in perovskite inks. ACS Energy Lett. 5, 1153–1155 (2020).

    Google Scholar 

  22. Ke, W., Stoumpos, C. C. & Kanatzidis, M. G. “Unleaded” perovskites: status quo and future prospects of tin‐based perovskite solar cells. Adv. Mater. 31, 1803230 (2019).

    Google Scholar 

  23. Wei, M. et al. Combining efficiency and stability in mixed tin–lead perovskite solar cells by capping grains with an ultrathin 2D layer. Adv. Mater. 32, 1907058 (2020).

    Google Scholar 

  24. Ni, Z. et al. Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells. Science 367, 1352–1358 (2020).

    Google Scholar 

  25. Czajkowski, W. & Misztal, J. The use of thiourea dioxide as reducing agent in the application of sulphur dyes. Dye. Pigment. 26, 77–81 (1994).

    Google Scholar 

  26. Krug, P. Thiourea dioxide (formamidinesulphinic acid) a new reducing agent for textile printing. J. Soc. Dye. Colour. 69, 606–611 (2008).

    Google Scholar 

  27. Lewis, D., Mama, J. & Hawkes, J. An investigation into the structure and chemical properties of formamidine sulfinic acid. Appl. Spectrosc. 68, 1327–1332 (2014).

    Google Scholar 

  28. Liu, C., Cheng, Y. & Ge, Z. Understanding of perovskite crystal growth and film formation in scalable deposition processes. Chem. Soc. Rev. 49, 8–12 (2020).

    Google Scholar 

  29. Zheng, X. et al. Dual functions of crystallization control and defect passivation enabled by sulfonic zwitterions for stable and efficient perovskite solar cells. Adv. Mater. 30, 1803428 (2018).

    Google Scholar 

  30. Wang, Z. et al. Passivation of grain boundary by squaraine zwitterions for defect passivation and efficient perovskite solar cells. ACS Appl. Mater. Interfaces 11, 10012–10020 (2019).

    Google Scholar 

  31. Chen, B., Rudd, P. N., Yang, S., Yuan, Y. & Huang, J. Imperfections and their passivation in halide perovskite solar cells. Chem. Soc. Rev. 48, 3842–3867 (2019).

    Google Scholar 

  32. Han, Q. et al. Low-temperature processed inorganic hole transport layer for efficient and stable mixed Pb-Sn low-bandgap perovskite solar cells. Sci. Bull. 64, 1399–1401 (2019).

    Google Scholar 

  33. Xu, J. et al. Crosslinked remote-doped hole-extracting contacts enhance stability under accelerated lifetime testing in perovskite solar cells. Adv. Mater. 28, 2807–2815 (2016).

    Google Scholar 

  34. Hayashi, N., Nishio, R. & Takada, S. Composition, film using the composition, charge transport layer, organic electroluminescence device, and method for forming charge transport layer. US patent US20120080666A1 (2012).

  35. Jošt, M. et al. 21.6%-efficient monolithic perovskite/Cu(In,Ga)Se2 tandem solar cells with thin conformal hole transport layers for integration on rough bottom cell surfaces. ACS Energy Lett. 4, 583–590 (2019).

    Google Scholar 

  36. Xu, J. et al. Triple-halide wide–band gap perovskites with suppressed phase segregation for efficient tandems. Science 367, 1097–1104 (2020).

    Google Scholar 

  37. Green, M. A. et al. Solar cell efficiency tables (version 51). Prog. Photovoltaics Res. Appl. 26, 3–12 (2018).

    Google Scholar 

  38. Jošt, M., Kegelmann, L., Korte, L. & Albrecht, S. Monolithic perovskite tandem solar cells: a review of the present status and advanced characterization methods toward 30% efficiency. Adv. Energy Mater. 10, 1904102 (2020).

    Google Scholar 

  39. Al-Ashouri, A. et al. Conformal monolayer contacts with lossless interfaces for perovskite single junction and monolithic tandem solar cells. Energy Environ. Sci. 12, 3356–3369 (2019).

    Google Scholar 

  40. Gharibzadeh, S. et al. Record open‐circuit voltage wide‐bandgap perovskite solar cells utilizing 2D/3D perovskite heterostructure. Adv. Energy Mater. 9, 1803699 (2019).

    Google Scholar 

  41. Godding, J. S. W. et al. Oxidative passivation of metal halide perovskites. Joule 3, 2716–2731 (2019).

    Google Scholar 

  42. Raiford, J. A. et al. Enhanced nucleation of atomic layer deposited contacts improves operational stability of perovskite solar cells in air. Adv. Energy Mater. 9, 1902353 (2019).

    Google Scholar 

  43. Seo, S., Jeong, S., Bae, C., Park, N.-G. & Shin, H. Perovskite solar cells with inorganic electron- and hole-transport layers exhibiting long-term (≈500 h) stability at 85 °C under continuous 1 sun illumination in ambient air. Adv. Mater. 30, 1801010 (2018).

    Google Scholar 

  44. Prasanna, R. et al. Design of low bandgap tin–lead halide perovskite solar cells to achieve thermal, atmospheric and operational stability. Nat. Energy 4, 939–947 (2019).

    Google Scholar 

  45. Shi, L. et al. Gas chromatography–mass spectrometry analyses of encapsulated stable perovskite solar cells. Science 368, eaba2412 (2020).

    Google Scholar 

  46. Wehrenfennig, C., Eperon, G. E., Johnston, M. B., Snaith, H. J. & Herz, L. M. High charge carrier mobilities and lifetimes in organolead trihalide perovskites. Adv. Mater. 26, 1584–1589 (2014).

    Google Scholar 

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This work is financially supported by the National Natural Science Foundation of China (61974063, 61921005), Fundamental Research Funds for the Central Universities (14380168), National Key R&D Program of China (2018YFB1500102), Natural Science Foundation of Jiangsu Province (BK20190315), Basic Research Program of Frontier Leading Technologies in Jiangsu Province, Program for Innovative Talents and Entrepreneur in Jiangsu and Thousand Talent Program for Young Outstanding Scientists in China. The work of Y.H., M.W. and E.H.S. is supported by US Department of the Navy, Office of Naval Research (N00014-20-1-2572). V.Y. and M.I.S. acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC).

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Authors and Affiliations



H.T. conceived and directed the overall project. K.X., R.L. and Q.H. fabricated all the devices and conducted the characterization. Y.H., M.I.S., V.Y., X.L., Z.Q., Y.W., J.W., H.G., C.Z., J.X. and J.Z. helped with the device fabrication and material characterization. M.W. performed the steady-state/transient PL and transient absorption measurements. H.T.N. performed the EL and PL imaging characterization. Y.G. performed the optical modelling of tandem devices. H.T. and K.X. wrote the draft, and E.H.S., M.I.S. and Y.H. improved the manuscript. All authors read and commented on the manuscript.

Corresponding author

Correspondence to Hairen Tan.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–29, Tables 1–6 and ref. 1.

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Supplementary Data

Normalized PV parameters of solar cells shown in Supplementary Fig. 28.

Source data

Source Data Fig. 3

PV parameters of solar cells shown in the Fig. 3b inset and Fig. 3e.

Source Data Fig. 4

PV parameters of solar cells shown in the Fig. 4g inset.

Source Data Fig. 5

Normalized PV parameters of solar cells shown in Fig. 5a.

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Xiao, K., Lin, R., Han, Q. et al. All-perovskite tandem solar cells with 24.2% certified efficiency and area over 1 cm2 using surface-anchoring zwitterionic antioxidant. Nat Energy 5, 870–880 (2020).

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