Tin-based perovskite solar cells (TPSCs) are among the best candidates for lead-free photovoltaic technology owing to their low toxicity and high theoretical efficiency. However, the efficiency and stability of TPSCs lag far behind their lead counterparts because of the poor controllability of perovskite film growth and the intrinsically easy oxidation of Sn²⁺. Here we synthesize two pyridyl-substituted fulleropyrrolidines (PPF) with cis (CPPF) and trans (TPPF) configurations and use them as precursor additives. The spatial configurations of the CPPF and TPPF greatly affect their electron density distributions and interactions with perovskite components. Compared with the CPPF, the TPPF has spatially separated pyridine groups that can catch more perovskite colloids through coordination bonds, thus slowing the perovskite crystallization process. The resultant perovskite film displayed better crystal orientation and compactness. The TPPF also remains located at the grain boundaries, improves the interface energy level alignment and suppresses Sn²⁺ oxidation. As a result, the TPPF-based TPSCs exhibit a high power conversion efficiency of 15.38% (certified 15.14%) and excellent stability, maintaining 99% and 93% of their initial efficiencies after 3,000 h of storage and 500 h of continuous illumination, respectively. This work highlights the importance of regulating coordination in the precursor solution in preparing high-quality tin-based perovskite films, paving the way to more efficient and stable TPSCs.

锡基钙钛矿太阳能电池（TPSC）由于其低毒性和高理论效率而成为无铅光伏技术的最佳候选者之一。^{然而，由于钙钛矿薄膜生长的可控性差以及Sn 2+}本质上容易氧化，TPSC的效率和稳定性远远落后于铅同类产品。在这里，我们合成了两种具有顺式（CPPF）和反式（TPPF）构型的吡啶基取代的富勒吡咯烷（PPF ），并将它们用作前体添加剂。CPPF 和 TPPF 的空间构型极大地影响它们的电子密度分布以及与钙钛矿组分的相互作用。与CPPF相比，TPPF具有空间分离的吡啶基团，可以通过配位键捕获更多的钙钛矿胶体，从而减缓钙钛矿结晶过程。所得钙钛矿薄膜表现出更好的晶体取向和致密性。TPPF还保持位于晶界处，改善界面能级排列并抑制Sn ²⁺氧化。因此，基于 TPPF 的 TPSC 表现出 15.38% 的高功率转换效率（认证为 15.14%）和出色的稳定性，在存储 3,000 小时和连续照明 500 小时后分别保持初始效率的 99% 和 93% 。这项工作强调了调节前驱体溶液中的配位在制备高质量锡基钙钛矿薄膜中的重要性，为更高效、更稳定的TPSC铺平了道路。