Zhang Chen, Hu Zhelu, Wang Jinpei, Zhu Jianbin, Hu Zhangquan, Dang Wenxiu, Guo Chunyu, Li Qiushi, Yang Jinxian, Zhang Bing, Ran Xueqin, Li Ping, Guo Qingxun, Chao Lingfeng, Xia Yingdong, Aigouy Lionel, Chen Zhuoying, Chen Yonghua, Huang Wei
State Key Laboratory of Flexible Electronics (LoFE) & Institute of Advanced Materials (IAM), School of Flexible Electronics (Future Technologies), Nanjing Tech University, Nanjing, 211816, China.
Laboratoire de Physique et d'Etude des Matériaux (LPEM), ESPCI Paris, PSL University, Sorbonne Université, CNRS UMR 8213, 10 Rue Vauquelin, Paris, F-75005, France.
Adv Mater. 2025 May 23:e2505581. doi: 10.1002/adma.202505581.
Mixed tin-lead (Sn-Pb) perovskites are integral to all-perovskite tandem solar cells (TSCs), offering significant potential to surpass the theoretical efficiency limits of single-junction solar cells. However, the rapid crystallization of Sn-Pb perovskite thin films and the propensity of Sn to oxidize into Sn remain critical challenges, hindering device performance and stability. Herein, it is demonstrated that a multifunctional dual-anion synergistic regulation strategy to fabricate high-quality MA-free CsFAPbSnI perovskite thin films with superior morphology and crystallinity via a simplified antisolvent-free spin-coating process. Acetate anions (Ac) derived from formamidinium acetate (FAAc) effectively regulate crystallization kinetics and mitigate Sn oxidation via intermediate phase formation and anion exchange process. Simultaneously, the combination of Ac and thiocyanate anions (SCN) from guanidinium thiocyanate (GuaSCN) promotes larger crystal grain growth and stabilizes Sn via strong coordination interactions. The dual-anion strategy effectively minimizes grain boundaries, suppresses non-radiative recombination, and optimizes the energy level alignment at interfaces. As a result, the champion single-junction Sn-Pb perovskite solar cell (PSC) achieves an impressive power conversion efficiency (PCE) of 23.26%, setting a new benchmark for Sn-Pb PSCs fabricated without antisolvent. While all-perovskite TSCs reach 28.07% efficiency with remarkable operational stability, retaining 81% of initial performance after 600 h under maximum power point tracking.
混合锡铅（Sn-Pb）钙钛矿对于全钙钛矿叠层太阳能电池（TSCs）至关重要，具有超越单结太阳能电池理论效率极限的巨大潜力。然而，Sn-Pb钙钛矿薄膜的快速结晶以及Sn氧化成Sn的倾向仍然是关键挑战，阻碍了器件性能和稳定性。在此，通过简化的无反溶剂旋涂工艺，展示了一种多功能双阴离子协同调控策略，以制备具有优异形貌和结晶度的无MA的CsFAPbSnI钙钛矿薄膜。源自乙酸甲脒（FAAc）的乙酸根阴离子（Ac）通过中间相形成和阴离子交换过程有效调节结晶动力学并减轻Sn氧化。同时，来自硫氰酸胍（GuaSCN）的Ac和硫氰酸根阴离子（SCN）的组合促进更大晶粒生长并通过强配位相互作用稳定Sn。双阴离子策略有效减少晶界，抑制非辐射复合，并优化界面处的能级排列。结果，冠军单结Sn-Pb钙钛矿太阳能电池（PSC）实现了令人印象深刻的23.26%的功率转换效率（PCE），为无反溶剂制备的Sn-Pb PSCs设定了新基准。而全钙钛矿TSCs的效率达到28.07%，具有出色的运行稳定性，在最大功率点跟踪下600小时后仍保留81%的初始性能。
