NATURE

By

Chenghao Duan, Kaicheng Zhang, Zijian Peng, Shiang Li, Feilin Zou, Feng Wang, Jiong Li, Zheng Zhang, Chang Chen, Qiliang Zhu, Jianhang Qiu, Xinhui Lu, Ning Li, Liming Ding, Christoph J. Brabec, Feng Gao & Keyou Yan

Published

28 November 2024

Abstract

All-inorganic perovskites prepared by substituting the organic cations (for example, methylammonium and formamidinium) with inorganic cations (for example, Cs+) are effective concepts to enhance the long-term photostability and thermal stability of perovskite solar cells (PSCs). Hence, inorganic perovskite tandem solar cells (IPTSCs) are promising candidates for breaking the efficiency bottleneck and addressing the stability issue, too. However, challenges remain in fabricating two-terminal (2T) IPTSCs due to the inferior film formation and deep trap states induced by tin cations. Here a ligand evolution (LE) strategy withp-toluenesulfonyl hydrazide (PTSH) is used to regulate film formation and eliminate deep traps in inorganic narrow-bandgap (NBG) perovskites, enabling the successful development of 2T IPTSCs. Accordingly, the 1.31 eV CsPb0.4Sn0.6I3:LE device delivers a record efficiency of 17.41%. Combined with the 1.92 eV CsPbI2Br top cell, 2T IPTSCs exhibit a champion efficiency of 22.57% (certified, 21.92%). Moreover, IPTSCs are engineered to deliver remarkable durability under maximum power point (MPP) tracking, maintaining 80% of their initial efficiency at 65 °C for 1,510 h and at 85 °C for 800 h. We elucidate that LE deliberately leverages multiple roles for inorganic NBG perovskite growth and anticipate that our study provides an insightful guideline for developing high-efficiency and stable IPTSCs.

Full Text Link

https://www.nature.com/articles/s41586-024-08432-7