Zhang Yao, Li Chunyan, Zhao Haiyan, Yu Zhongxun, Tang Xiaoan, Zhang Jixiang, Chen Zhenhua, Zeng Jianrong, Zhang Peng, Han Liyuan, Chen Han
State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, China.
Innovation Center for Future Materials, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai, China.
Nat Commun. 2024 Aug 12;15(1):6887. doi: 10.1038/s41467-024-51361-2.
Tin-lead halide perovskites with a bandgap near 1.2 electron-volt hold great promise for thin-film photovoltaics. However, the film quality of solution-processed Sn-Pb perovskites is compromised by the asynchronous crystallization behavior between Sn and Pb components, where the crystallization of Sn-based perovskites tends to occur faster than that of Pb. Here we show that the rapid crystallization of Sn is rooted in its stereochemically active lone pair, which impedes coordination between the metal ion and Lewis base ligands in the perovskite precursor. From this perspective, we introduce a noncovalent binding agent targeting the open metal site of coordinatively unsaturated Sn(II) solvates, thereby synchronizing crystallization kinetics and homogenizing Sn-Pb alloying. The resultant single-junction Sn-Pb perovskite solar cells achieve a certified power conversion efficiency of 24.13 per cent. The encapsulated device retains 90 per cent of the initial efficiency after 795 h of maximum power point operation under simulated one-sun illumination.
带隙接近1.2电子伏特的锡铅卤化物钙钛矿在薄膜光伏领域极具潜力。然而，溶液法制备的锡铅钙钛矿的薄膜质量因锡和铅组分之间的异步结晶行为而受损，其中锡基钙钛矿的结晶往往比铅的结晶更快。在此，我们表明锡的快速结晶源于其立体化学活性孤对电子，这阻碍了金属离子与钙钛矿前驱体中路易斯碱配体之间的配位。从这个角度出发，我们引入了一种针对配位不饱和锡（II）溶剂化物开放金属位点的非共价结合剂，从而同步结晶动力学并使锡铅合金化均匀化。由此得到的单结锡铅钙钛矿太阳能电池实现了24.13%的认证功率转换效率。在模拟的一个太阳光照下最大功率点运行795小时后，封装器件保留了初始效率的90%。
