Current Photovoltaic Research

Korea Photovoltaic Society (한국태양광발전학회)
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Recent Advances in the Development of High-Efficiency All-Perovskite Tandem Solar Cells

고효율 페로브스카이트-페로브스카이트 탠덤 태양전지의 연구 개발 동향

  • Jaehyeok Koh (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Chaeyoun Kim (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Seongju Park (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Dayeon Woo (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Byungha Shin (Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST))
  • 고재혁 (신소재공학과, 한국과학기술원) ;
  • 김채연 (신소재공학과, 한국과학기술원) ;
  • 박성주 (신소재공학과, 한국과학기술원) ;
  • 우다연 (신소재공학과, 한국과학기술원) ;
  • 신병하 (신소재공학과, 한국과학기술원)
  • Received : 2024.09.09
  • Accepted : 2024.09.20
  • Published : 2024.09.30
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Abstract

All-perovskite tandem solar cells have been developed as a next-generation solar cell technology to surpass the efficiency limits of single-junction solar cells. By using perovskite materials with different bandgaps in the top and bottom cells, these tandem solar cells can effectively utilize a wider range of the solar spectrum. All-perovskite tandem solar cells have been focused as a next-generation solar cell due to their ability to achieve high efficiency while being manufactured through low-cost solution processing. This paper focuses on key components for improving the performance of all-perovskite tandem solar cells and essential components: wide bandgap perovskite solar cells, narrow bandgap perovskite solar cells, and charge recombination layers. The characteristics, main challenges, and strategies for overcoming these issues are discussed. For wide bandgap perovskites, efficiency is reduced by high trap densities and halide ion phase segregation. Improvement methods through additives and surface passivation are proposed to overcome these issues. In narrow bandgap perovskites, composition control and surface treatment techniques are being developed to reduce the oxidation of Sn-based materials and charge recombination in the perovskite. Additionally, the charge recombination layer is an essential component for efficient electron-hole recombination and minimizing optical losses, with materials such as transparent conductive oxides and ultrathin metals being used. These studies make a significant contribution to enhancing the efficiency and stability of all-perovskite tandem solar cells and suggest future research directions for commercialization.

Keywords

References

  1. Z. Zhang, Z. Li, L. Meng, S.-Y. Lien, P. Gao, Perovskite-based tandem solar cells: Get the most out of the sun. Adv. Funct. Mater. 30, 2001904 (2020).
  2. A. R. Bowman, F. Lang, Y.-H. Chiang, A. Jimenez-Solano, K. Frohna, G. E. Eperon, E. Ruggeri, M. Abdi-Jalebi, M. Anaya, B. V. Lotsch, S. D. Stranks, Relaxed current matching requirements in highly luminescent perovskite tandem solar cells and their fundamental efficiency limits. ACS Energy Lett. 6, 612-620 (2021).
  3. J. Lim, N.-G. Park, S. I. Seok, M. Saliba, All-perovskite tandem solar cells: from fundamentals to technological progress. Energy Environ. Sci. 17, 4390 (2024).
  4. Best Research-Cell Efficiencies. https://www.nrel.gov/pv/cell-efficiency.html. (accessed on 18 September 2024)
  5. N. J. Jeon, J. H. Noh, Y. C. Kim, W. S. Yang, S. Ryu, S. I. Seok, Solvent engineering for high-performance inorganic-organic hybrid perovskite solar cells. Nat. Mater. 13, 897-903 (2014).
  6. Y. Liu, P.-A. Chen, X. Qiu, J. Guo, J. Xia, H. Wei, H. Xie, S. Hou, M. He, X. Wang, Z. Zeng, L. Jiang, L. Liao, Y. Hu, Doping of Sn-based two-dimensional perovskite semiconductor for high-performance field-effect transistors and thermoelectric devices. Iscience. 25, 104109 (2022).
  7. Y. Guo, S. Yuan, D. Zhu, M. Yu, H.-Y. Wang, J. Lin, Y. Wang, Y. Qin, J.-P. Zhang, X.-C. Ai, Influence of the MACl additive on grain boundaries, trap-state properties, and charge dynamics in perovskite solar cells. Phys. Chem. Chem. Phys. 23, 6162-6170 (2021).
  8. C. Wang, Y. Zhao, T. Ma, Y. An, R. He, J. Zhu, C. Chen, S. Ren, F. Fu, D. Zhao, X. Li, A universal close-space annealing strategy towards high-quality perovskite absorbers enabling efficient all-perovskite tandem solar cells. Nat. Energy. 7, 744-753 (2022).
  9. J. Wang, G. Jin, Q. Zhen, C. He, Y. Duan, Bulk passivation and interfacial passivation for perovskite solar cells: Which one is more effective? Adv. Mater. Interfaces. 8, 2002078 (2021).
  10. M. Zhang, Z. Lin, Efficient interconnecting layers in monolithic all-perovskite tandem solar cells. Energy Environ. Sci. 15, 3152-3170 (2022).
  11. R. Lin, K. Xiao, Z. Qin, Q. Han, C. Zhang, M. Wei, M. I. Saidaminov, Y. Gao, J. Xu, M. Xiao, A. Li, J. Zhu, E. H. Sargent, H. Tan, 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).
  12. R. Sheng, M. T. Horantner, Z. Wang, Y. Jiang, W. Zhang, A. Agosti, S. Huang, X. Hao, A. Ho-Baillie, M. Green, H. J. Snaith, Monolithic wide band gap perovskite/perovskite tandem solar cells with organic recombination layers. J. Phys. Chem. C. 121, 27256-27262 (2017).
  13. Z. Yu, Z. Yang, Z. Ni, Y. Shao, B. Chen, Y. Lin, H. Wei, Z. J. Yu, Z. Holman, J. Huang, Simplified interconnection structure based on C60/SnO2-x for all-perovskite tandem solar cells. Nat. Energy. 5, 657-665 (2020).
  14. E. T. Hoke, D. J. Slotcavage, E. R. Dohner, A. R. Bowring, H. I. Karunadasa, M. D. McGehee, Reversible photo-induced trap formation in mixed-halide hybrid perovskites for photovoltaics. Chem. Sci. 6, 613-617 (2015).
  15. R. He, T. Chen, Z. Xuan, T. Guo, J. Luo, Y. Jiang, W. Wang, J. Zhang, X. Hao, L. Wu, Y. Wang, I. Constantinou, S. Ren, D. Zhao, Efficient wide-bandgap perovskite solar cells enabled by doping a bromine-rich molecule. Nanophotonics. 10, 2059-2068 (2021).
  16. H. Guan, S. Zhou, S. Fu, D. Pu, X. Chen, Y. Ge, S. Wang, C. Wang, H. Cui, J. Liang, X. Hu, W. Meng, G. Fang, W. Ke, Regulating crystal orientation via ligand anchoring enables efficient wide-bandgap perovskite solar cells and tandems. Adv. Mater. 36, 2307987 (2023).
  17. D. H. Kim, C. P. Muzzillo, J. Tong, A. F. Palmstrom, B. W. Larson, C. Choi, S. P. Harvey, S. Glynn, J. B. Whitaker, F. Zhang, Z. Li, H. Lu, M. F. A. M. van Hest, J. J. Berry, L. M. Mansfield, Y. Huang, Y. Yan, K. Zhu, Bimolecular additives improve wide-band-gap perovskites for efficient tandem solar cells with CIGS. Joule. 3, 1734-1745 (2019).
  18. C. Zhao, B. Jiang, Y. Huang, X. Sun, M. Wang, Y. Zhang, N. Zhang, Highly active and stable oxygen vacancies via sulfur modification for efficient catalysis in lithium-sulfur batteries. Energy Environ. Sci. 16, 5490-5499 (2023).
  19. H. Lee, P. Boonmongkolras, S. Jun, D. Kim, Y. Park, J. Koh, Y.-H. Cho, B. Shin, J. Y. Park, In situ observation of photoinduced halide segregation in mixed halide perovskite. ACS Appl. Energy Mater. 6, 1565-1574 (2023).
  20. G. Kim, C. S. Moon, T.-Y. Yang, Y. Y. Kim, J. Chung, E. H. Jung, T. J. Shin, N. J. Jeon, H. H. Park, J. Seo, A thermally induced perovskite crystal control strategy for efficient and photostable wide-bandgap perovskite solar cells. Sol. RRL. 4, 2000033 (2020).
  21. J. Wen, Y. Zhao, Z. Liu, H. Gao, R. Lin, S. Wan, C. Ji, K. Xiao, Y. Gao, Y. Tian, J. Xie, C. J. Brabec, H. Tan, Steric engineering enables efficient and photostable wide-bandgap perovskites for all-perovskite tandem solar cells. Adv. Mater. 34, 2110356 (2022).
  22. J. Cho, P. V. Kamat, How chloride suppresses photoinduced phase segregation in mixed halide perovskites. Chem. Mater. 32, 6206-6212 (2020).
  23. H. Chen, A. Maxwell, C. Li, S. Teale, B. Chen, T. Zhu, E. Ugur, G. Harrison, L. Grater, J. Wang, Z. Wang, L. Zeng, S. M. Park, L. Chen, P. Serles, R. A. Awni, B. Subedi, X. Zheng, C. Xiao, N. J. Podraza, T. Filleter, C. Liu, Y. Yang, J. M. Luther, S. De Wolf, M. G. Kanatzidis, Y. Yan, E. H. Sargent, Regulating surface potential maximizes voltage in all-perovskite tandems. Nature. 613, 676-681 (2023).
  24. L. Li, Y. Wang, X. Wang, R. Lin, X. Luo, Z. Liu, K. Zhou, S. Xiong, Q. Bao, G. Chen, Y. Tian, Y. Deng, K. Xiao, J. Wu, M. I. Saidaminov, H. Lin, C.-Q. Ma, Z. Zhao, Y. Wu, L. Zhang, H. Tan, Flexible all-perovskite tandem solar cells approaching 25% efficiency with molecule-bridged hole-selective contact. Nat. Energy. 7, 708-717 (2022).
  25. X. Y. Chin, D. Turkay, J. A. Steele, S. Tabean, S. Eswara, M. Mensi, P. Fiala, C. M. Wolff, A. Paracchino, K. Artuk, D. Jacobs, Q. Guesnay, F. Sahli, G. Andreatta, M. Boccard, Q. Jeangros, C. Ballif, Interface passivation for 31.25%-efficient perovskite/silicon tandem solar cells. Science. 381, 59-63 (2023).
  26. F. Hao, C. C. Stoumpos, D. H. Cao, R. P. H. Chang, M. G. Kanatzidis. Lead-free solid-state organic-inorganic halide perovskite solar cells. Nature Photon. 8, 489-494 (2014).
  27. W. Liao, D. Zhao, Y. Yu, C. R. Grice, C. Wang, A. J. Cimaroli, P. Schulz, W. Meng, K. Zhu, R.-G. Xiong, Y. Yan, Lead-free inverted planar formamidinium tin triiodide perovskite solar cells achieving power conversion efficiencies up to 6.22%. Adv. Mater. 28, 9333-9340 (2016).
  28. E. Jokar, C.-H. Chien, A. Fathi, M. Rameez, Y.-H. Chang, E. W.-G. Diau, Slow surface passivation and crystal relaxation with additives to improve device performance and durability for tin-based perovskite solar cells. Energy Environ. Sci. 11, 2353-2362 (2018).
  29. Y. Ogomi, A. Morita, S. Tsukamoto, T. Saitho, N. Fujikawa, Q. Shen, T. Toyoda, K. Yoshino, S. S. Pandey, T. Ma, S. Hayase, CH3NH3SnxPb(1-x)I3 perovskite solar cells covering up to 1060 nm. J. Phys. Chem. Lett. 5, 1004-1011 (2014).
  30. A. Rajagopal, P.-W. Liang, C.-C. Chueh, Z. Yang, A. K.-Y. Jen, Defect passivation via a graded fullerene heterojunction in low-bandgap Pb-Sn binary perovskite photovoltaics. ACS Energy Lett. 2, 2531-2539 (2017).
  31. Z. Yang, A. Rajagopal, C. -C. Chueh, S. B. Jo, B. Liu, T. Zhao, A. K.-Y. Jen, Stable Low-Bandgap Pb-Sn Binary Perovskites for Tandem Solar Cells. Adv. Mater. 28, 8990-8997 (2016).
  32. C. Li, Z. Song, D. Zhao, C. Xiao, B. Subedi, N. Shrestha, M. M. Junda, C. Wang, C. S. Jiang, M. Al-Jassim, R. J. Ellingson, N. J. Podraza, K. Zhu, Y. Yan, Reducing saturation-current density to realize high-efficiency low-bandgap mixed tin-lead halide perovskite solar cells. Adv. Energy Mater. 9, 1803135 (2019).
  33. J. Cao, H. L. Loi, Y. Xu, X. Guo, N. Wang, C. Liu, T. Wang, H. Cheng, Y. Zhu, M. G. Li, W. Y. Wong, F. Yan, High-performance tin-lead mixed-perovskite solar cells with vertical compositional gradient. Adv. Mater. 34, 2107729 (2022).
  34. R. Lin, Y. Wang, Q. Lu, B. Tang, J. Li, H. Gao, Y. Gao, H. Li, C. Ding, J. Wen, P. Wu, C. Liu, S. Zhao, K. Xiao, Z. Liu, C. Ma, Y. Deng, L. Li, F. Fan, H. Tan, All-perovskite tandem solar cells with 3D/3D bilayer perovskite heterojunction. Nature. 620, 994-1000 (2023).
  35. C. Yi, J. Luo, S. Meloni, A. Boziki, N. Ashari-Astani, C. Gratzel, S. M. Zakeeruddin, U. Rothlisberger, M. Gratzel, Entropic stabilization of mixed A-cation ABX3 metal halide perovskites for high performance perovskite solar cells. Energy Environ. Sci. 9, 656-662 (2016).
  36. S. Hu, K. Otsuka, R. Murdey, T. Nakamura, M. A. Truong, T. Yamada, T. Handa, K. Matsuda, K. Nakano, A. Sato, K. Marumoto, K. Tajima, Y. Kanemitsu, A. Wakamiya, Optimized carrier extraction at interfaces for 23.6% efficient tin-lead perovskite solar cells. Energy Environ. Sci. 15, 2096 (2022).
  37. W. Chi, S. K. Banerjee, K. G. D. I. Jayawardena, S. R. P. Silva, S. I. Seok, Perovskite/Silicon tandem solar cells: Choice of bottom devices and recombination layers. ACS Energy Lett. 8, 1535-1550 (2023).
  38. M. Zhang, Z. Lin, Efficient interconnecting layers in monolithic all-perovskite tandem solar cells. Energy Environ. Sci. 15, 3152 (2022).
  39. Y. Lin, W. Yang, H. Gu, F. Du, J. Liao, D. Yu, J. Xia, H. Wang, S. Yang, G. Fang, C. Liang, Transparent recombination layers design and rational characterizations for efficient two-terminalperovskite-based tandem solar cells. Adv. mater. 36, 2405684 (2024).
  40. Z. Ma, Y. Dong, R. Wang, Z. Xu, M. Li, Z. Tan, Transparent recombination electrode with dual-functionaltransport and protective layer for efficient and stable monolithic perovskite/organic tandem solar cells. Adv. Mater. 35, 2307052 (2023).
  41. Q. Yang, W. Duan, A. Eberst, B. Klingebiel, Y. Wang, A. Kulkarni, A. Lambertz, K. Bittkau, Y. Zhang, S. Vitusevich, U. Rau, T. Kirchartz, K. Ding, Origin of sputter damage during transparent conductive oxide deposition for semitransparent perovskite solar cells. J. Mater. Chem. A. 12, 14816 (2024).
  42. K. A. Bush, A. F. Palmstrom, Z. J. Yu, M. Boccard, R. Cheacharoen, J. P. Mailoa, D. P. McMeekin, R. L. Z. Hoye, C. D. Bailie, T. Leijtens, I. M. Peters, M. C. Minichetti, N. Rolston, R. Prasanna, S. Sofia, D. Harwood, W. Ma, F. Moghadam, H. J. Snaith, T. Buonassisi, Z. C. Holman, S. F. Bent, M. D. McGehee, 23.6%-efficient monolithic perovskite/silicon tandem solar cells with improved stability. Nat. Energy. 2, 17009 (2017).
  43. G. E. Eperon, T. Leijtens, K. A. Bush, R. Prasanna, T. Green, J. T.-W. Wang, D. P. McMeekin, G. Volonakis, R. L. Milot, R. May, A. Palmstrom, D. J. Slotcavage, R. A. Belisle, J. B. Patel, E. S. Parrott, R. J. Sutton, W. Ma, F. Moghadam, B. Conings, A. Babayigit, H.-G. Boyen, S. Bent, F. Giustino, L. M. Herz, M. B. Johnston, M. D. McGehee, H. J. Snaith, Perovskite-perovskite tandem photovoltaics with optimized band gaps. Science. 354, 861-865 (2016).
  44. D. Zhao, C. Chen, C. Wang, M. M. Junda, Z. Song, C. R. Grice, Y. Yu, C. Li, B. Subedi, N. J. Podraza, X. Zhao, G. Fang, R.-G. Xiong, K. Zhu, Y. Yan, Efficient two-terminal all-perovskite tandem solar cells enabled by high-quality low-bandgap absorber layers. Nat. Energy. 3, 1093-1100 (2018).
  45. A. F. Palmstrom, G. E. Eperon, T. Leijtens, R. Prasanna, S. N. Habisreutinger, W. Nemeth, E. A. Gaulding, S. P. Dunfield, M. Reese, S. Nanayakkara, T. Moot, J. Werner, J. Liu, B. To, S. T. Christensen, M. D. McGehee, M. F. A. M. van Hest, J. M. Luther, J. J. Berry, D. T. Moore, Enabling Flexible All-Perovskite Tandem Solar Cells. Joule. 3, 2193-2204 (2019).
  46. C. Li, Z. S. Wang, H. L. Zhu, D. Zhang, J. Cheng, H. Lin, D. Ouyang, W. C. H. Choy, Thermionic emission-based interconnecting layer featuring solvent resistance for monolithic tandem solar cells with solution-processed perovskites. Adv. Energy Mater. 8, 1801954 (2018).
  47. R. Lin, K. Xiao, Z. Qin, Q. Han, C. Zhang, M. Wei, M. I. Saidaminov, Y. Gao, J. Xu, M. Xiao, A. Li, J. Zhu, E. H. Sargent, H. Tan, 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).
  48. K. Xiao, J. Wen, Q. Han, R. Lin, Y. Gao, S. Gu, Y. Zang, Y. Nie, J. Zhu, J. Xu, H. Tan, Solution-processed monolithic all-perovskite triple-junction solar cells with efficiency exceeding 20%. ACS Energy Lett. 5, 2819-2826 (2020).
  49. R. Lin, J. Xu, M. Wei, Y. Wang, Z. Qin, Z. Liu, J. Wu, K. Xiao, B. Chen, S. M. Park, G. Chen, H. R. Atapattu, K. R. Graham, J. Xu, J. Zhu, L. Li, C. Zhang, E. H. Sargent, H. Tan, All-perovskite tandem solar cells with improved grain surface passivation. Nature. 603, 73-78 (2022).
  50. R. Lin, Y. Wang, Q. Lu, B. Tang, J. Li, H. Gao, Y. Gao, H. Li, C. Ding, J. Wen, P. Wu, C. Liu, S. Zhao, K. Xiao, Z. Liu, C. Ma, Y. Deng, L. Li, F. Fan, H. Tan, All-perovskite tandem solar cells with 3D/3D bilayer perovskite heterojunction. Nature. 620, 994-1000 (2023).
  51. S. Zhou, S. Fu, C. Wang, W. Meng, J. Zhou, Y. Zou, Q. Lin, L. Huang, W. Zhang, G. Zeng, D. Pu, H. Guan, C. Wang, K. Dong, H. Cui, S. Wang, T. Wang, G. Fang, W. Ke, Aspartate all-in-one doping strategy enables efficient all-perovskite tandems. Nature. 624, 69-73 (2023).
  52. J. Zhou, H. Qiu, T. Wen, Z. He, C. Zou, Y. Shi, L. Zhu, C.-C. Chen, G. Liu, S. Yang, F. Liu, Z. Yang, Acidity control of interface for improving stability of all-perovskite tandem solar cells. Adv. Energy Mater. 13, 2300968 (2023).
  53. H. Bi, J. Liu, Z. Zhang, L. Wang, R. Beresneviciute, D. Tavgeniene, G. Kapil, C. Ding, A. K. Baranwal, S. R. Sahamir, Y. Sanehira, H. Segawa, S. Grigalvicius, Q. Shen, S. Hayase, All-perovskite tandem solar cells approach 26.5% efficiency by employing wide bandgap lead perovskite solar cells with new monomolecular hole transport layer. ACS Energy Lett. 8, 3852-3859 (2023).
  54. Y. Wang, R. Lin, X. Wang, C. Liu, Y. Ahmed, Z. Huang, Z. Zhang, H. Li, M. Zhang, Y. Gao, H. Luo, P. Wu, H. Gao, X. Zheng, M. Li, Z. Liu, W. Kong, L. Li, K. Liu, M. I. Saidaminov, L. Zhang, H. Tan, Oxidation-resistant all-perovskite tandem solar cells in substrate configuration. Nat. Commun. 14, 1819 (2023).
  55. Y.-H. Chiang, K. Frohna, H. Salway, A. Abfalterer, L. Pan, B. Roose, M. Anaya, S. D. Stranks, Vacuum-deposited wide-bandgap perovskite for all-perovskite tandem solar cells. ACS Energy Lett. 8, 2728-2737 (2023).
  56. T. Li, J. Xu, R. Lin, S. Teale, H. Li, Z. Liu, C. Duan, Q. Zhao, K. Xiao, P. Wu, B. Chen, S. Jiang, S. Xiong, H. Luo, S. Wan, L. Li, Q. Bao, Y. Tian, X. Gao, J. Xie, E. H. Sargent, H. Tan, Inorganic wide-bandgap perovskite subcells with dipole bridge for all-perovskite tandems. Nat. Energy. 8, 610-620 (2023).
  57. R. He, W. Wang, Z. Yi, F. Lang, C. Chen, J. Luo, J. Zhu, J. Thiesbrummel, S. Shah, K. Wei, Y. Luo, C. Wang, H. Lai, H. Huang, J. Zhou, B. Zou, X. Yin, S. Ren, X. Hao, L. Wu, J. Zhang, J. Zhang, M. Stolterfoht, F. Fu, W. Tang, D. Zhao, Improving interface quality for 1-cm2 all-perovskite tandem solar cells. Nature, 618, 80-86 (2023).
  58. D. Yu, M. Pan, G. Liu, X. Jiang, X. Wen, W. Li, S. Chen, W. Zhou, H. Wang, Y. Lu, M. Ma, Z. Zang, P. Cheng, Q. Ji, F. Zheng, Z. Ning, Electron-withdrawing organic ligand for high-efficiency all-perovskite tandem solar cells. Nat. Energy. 9, 298-307 (2024).
  59. H. Sun, K. Xiao, H. Gao, C. Duan, S. Zhao, J. Wen, Y. Wang, R. Lin, X. Zheng, H. Luo, C. Liu, P. Wu, W. Kong, Z. Liu, L. Li, H. Tan, Scalable solution-processed hybrid electron transport layers for efficient all-perovskite tandem solar modules. Adv. Mater. 36, 2308706 (2024).
  60. Q. Sun, Z. Zhang, H. Yu, J. Huang, X. Li, L. Dai, Q. Wang, Y. Shen, M. Wang, Surface charge transfer doping of narrow-bandgap Sn-Pb perovskites for high-performance tandem solar cells. Energy Environ. Sci. 17, 2512 (2024).
  61. J. Zhou, S. Fu, S. Zhou, L. Huang, C. Wang, H. Guan, D. Pu, H. Cui, C. Wang, T. Wang, W. Meng, G. Fang, W. Ke, Mixed tin-lead perovskites with balanced crystallization and oxidation barrier for all-perovskite tandem solar cells. Nat. Commun. 15, 2324 (2024).