Feng Wenhuai, Tao Junlei, Liu Gengling, Yang Guo, Zhong Jun-Xing, Fang Yuxuan, Gong Li, Yang Shaopeng, Wu Wu-Qiang
Key Laboratory of Bioinorganic and Synthetic Chemistry (MoE), Lehn Institute of Functional Materials, School of Chemistry, Sun Yat-sen University, Guangzhou, 510006, China.
Province-Ministry Co-construction Collaborative Innovation Center of Hebei Photovoltaic Technology, College of Physics Science and Technology, Hebei University, Baoding, 071002, China.
Angew Chem Int Ed Engl. 2023 Apr 17;62(17):e202300265. doi: 10.1002/anie.202300265. Epub 2023 Mar 13.
Mixed-cation, small band-gap perovskites via rationally alloying formamidinium (FA) and methylammonium (MA) together have been widely employed for blade-coated perovskite solar cells with satisfied efficiencies. One of the stringent challenges lies in difficult control of the nucleation and crystallization kinetics of the perovskites with mixed ingredients. Herein, a pre-seeding strategy by mixing FAPbI solution with pre-synthesized MAPbI microcrystals has been developed to smartly decouple the nucleation and crystallization process. As a result, the time window of initialized crystallization has been greatly extended by 3 folds (i.e. from 5 s to 20 s), which enables the formation of uniform and homogeneous alloyed-FAMA perovskite films with designated stoichiometric ratios. The resultant blade-coated solar cells achieved a champion efficiency of 24.31 % accompanied by outstanding reproducibility with more than 87 % of the devices showing efficiencies higher than 23 %.
通过合理地将甲脒（FA）和甲基铵（MA）合金化而制备的混合阳离子、小带隙钙钛矿已被广泛应用于具有令人满意效率的刮刀涂布钙钛矿太阳能电池。一个严峻的挑战在于难以控制含有混合成分的钙钛矿的成核和结晶动力学。在此，开发了一种通过将FAPbI溶液与预先合成的MAPbI微晶混合的预播种策略，以巧妙地解耦成核和结晶过程。结果，初始结晶的时间窗口大大延长了3倍（即从5秒延长到20秒），这使得能够形成具有指定化学计量比的均匀且均质的合金化FAMA钙钛矿薄膜。由此得到的刮刀涂布太阳能电池实现了24.31%的最高效率，同时具有出色的重现性，超过87%的器件效率高于23%。
