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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Min, H. et al. Efficient, stable solar cells by using inherent bandgap of a-phase formamidinium lead iodide. Science 366, 749–753 (2019).
Jiang, Q. et al. Surface passivation of perovskite film for efficient solar cells. Nat. Photon. 13, 460–466 (2019).
Green, M. A. et al. Solar cell efficiency tables (version 55). Prog. Photovoltaics Res. Appl. 28, 3–15 (2020).
Eperon, G. E., Hörantner, M. T. & Snaith, H. J. Metal halide perovskite tandem and multiple-junction photovoltaics. Nat. Rev. Chem. 1, 0095 (2017).
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).
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).
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).
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).
Eperon, G. E. et al. Perovskite-perovskite tandem photovoltaics with optimized band gaps. Science 354, 861–865 (2016).
Palmstrom, A. F. et al. Enabling flexible all-perovskite tandem solar cells. Joule 3, 2193–2204 (2019).
Rong, Y. et al. Challenges for commercializing perovskite solar cells. Science 361, eaat8235 (2018).
Park, N., Grätzel, M., Miyasaka, T., Zhu, K. & Emery, K. Towards stable and commercially available perovskite solar cells. Nat. Energy 1, 16152 (2016).
Park, N.-G. & Zhu, K. Scalable fabrication and coating methods for perovskite solar cells and solar modules. Nat. Rev. Mater. 5, 333–350 (2020).
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).
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).
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).
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).
Konstantakou, M. & Stergiopoulos, T. A critical review on tin halide perovskite solar cells. J. Mater. Chem. A 5, 11518–11549 (2017).
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).
Tai, Q. et al. Antioxidant grain passivation for air-stable tin-based perovskite solar cells. Angew. Chem. Int. Ed. 58, 806–810 (2019).
Saidaminov, M. I. et al. Conventional solvent oxidizes Sn(II) in perovskite inks. ACS Energy Lett. 5, 1153–1155 (2020).
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).
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).
Ni, Z. et al. Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells. Science 367, 1352–1358 (2020).
Czajkowski, W. & Misztal, J. The use of thiourea dioxide as reducing agent in the application of sulphur dyes. Dye. Pigment. 26, 77–81 (1994).
Krug, P. Thiourea dioxide (formamidinesulphinic acid) a new reducing agent for textile printing. J. Soc. Dye. Colour. 69, 606–611 (2008).
Lewis, D., Mama, J. & Hawkes, J. An investigation into the structure and chemical properties of formamidine sulfinic acid. Appl. Spectrosc. 68, 1327–1332 (2014).
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).
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).
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).
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).
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).
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).
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).
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).
Xu, J. et al. Triple-halide wide–band gap perovskites with suppressed phase segregation for efficient tandems. Science 367, 1097–1104 (2020).
Green, M. A. et al. Solar cell efficiency tables (version 51). Prog. Photovoltaics Res. Appl. 26, 3–12 (2018).
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).
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).
Gharibzadeh, S. et al. Record open‐circuit voltage wide‐bandgap perovskite solar cells utilizing 2D/3D perovskite heterostructure. Adv. Energy Mater. 9, 1803699 (2019).
Godding, J. S. W. et al. Oxidative passivation of metal halide perovskites. Joule 3, 2716–2731 (2019).
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).
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).
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).
Shi, L. et al. Gas chromatography–mass spectrometry analyses of encapsulated stable perovskite solar cells. Science 368, eaba2412 (2020).
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).
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).
The authors declare no competing interests.
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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 (2020). https://doi.org/10.1038/s41560-020-00705-5