Tin-based perovskite solar cells (TPSCs) as the most promising candidate for lead-free PSCs have incurred extensive researches all over the world. However, the crystallization process of tin-based perovskite is too fast during the solution-deposited process, resulting in abundant pinholes and poor homogeneity that cause serious charge recombination in perovskite layer. Here, we employed the π-conjugated Lewis base molecules with high electron density to systematically control the crystallization rate of FASnI₃ perovskite by forming stable intermediate phase with the Sn-I frameworks, leading to a compact and uniform perovskite film with large increase in the carrier lifetime. Meanwhile, the introduction of the π-conjugated systems also retards the permeation of moisture into perovskite crystal, which significantly suppresses the film degradation in air. These benefits contributed to a stabilizing power conversion efficiency (PCE) of 10.1% for the TPSCs and maintained over 90% of its initial PCE after 1000-h light soaking in air. Also, a steady-state efficiency of 9.2% was certified at the accredited test center.

中文翻译：

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通过引入π共轭Lewis碱，高效稳定的锡基钙钛矿太阳能电池

锡基钙钛矿太阳能电池（TPSC）作为无铅PSC的最有希望的候选者，已经在世界范围内进行了广泛的研究。然而，在溶液沉积过程中，锡基钙钛矿的结晶过程太快，导致大量针孔和均质性差，从而导致钙钛矿层中的电荷严重复合。在这里，我们使用具有高电子密度的π共轭Lewis分子来系统地控制FASnI ₃的结晶速率通过与Sn-I骨架形成稳定的中间相形成钙钛矿，从而形成致密而均匀的钙钛矿薄膜，并大大延长了载流子的使用寿命。同时，π共轭体系的引入还阻碍了水分渗透到钙钛矿晶体中，这显着抑制了空气中膜的降解。这些优点使TPSC的电源转换效率（PCE）稳定了10.1％，并且在空气中浸泡1000小时后，其初始PCE保持了90％以上。此外，经认可的测试中心还证明了9.2％的稳态效率。