Tin halide perovskite solar cells (TPSCs) have attracted extensive attention because of their low toxicity and high theoretical efficiency. However, rapid crystallization, rich defects, and easy oxidation of tin-based perovskite films seriously restrict solar cell performance. Herein, a composition and additive engineering solution by removing commonly used tin fluoride additive from formamidinium tin triiodide perovskite precursors and replacing it with excess tin (II) iodide and ethylenediamine dihydroiodide (EDAI₂) is adopted. The presence of EDAI₂ and excess SnI₂ and the absence of SnF₂ enable tin-based perovskite films with greatly improved morphology, enhanced crystalline quality, boosted optical properties, and prolonged carrier lifetime. Therefore, the SnF₂-free non-stoichiometric TPSCs employing the EDAI₂ additive and excess SnI₂ have increased built-in potential, lowered dark currents, and reduced carrier recombination. The resulting SnF₂-free and SnI₂-rich TPSCs with EDAI₂ addition realize a steady-state efficiency of 10.0%, which is one of the highest power conversion efficiencies among the SnF₂-free TPSCs, along with considerably improved light stability. This work highlights the crucial roles of additives in TPSCs and provides an effective strategy to fabricate efficient and stable low-toxic lead-free perovskite solar cells.

中文翻译：

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通过成分和添加剂工程实现高效无氟甲脒三碘化锡钙钛矿太阳能电池

卤化锡钙钛矿太阳能电池（TPSCs）因其低毒性和高理论效率而受到广泛关注。然而，锡基钙钛矿薄膜结晶快、缺陷多、易氧化等问题严重制约了太阳能电池的性能。_{在此，采用从甲脒三碘化锡钙钛矿前体中去除常用的氟化锡添加剂并用过量的碘化锡（II）和乙二胺二氢碘化物（EDAI 2}）代替的组成和添加剂工程解决方案。存在 EDAI ₂和过量的 SnI ₂并且不存在 SnF ₂使锡基钙钛矿薄膜具有显着改善的形态、增强的结晶质量、增强的光学性能和延长的载流子寿命。因此，使用 EDAI ₂添加剂和过量 SnI _{2的不含 SnF 2}的非化学计量 TPSC具有增加的内置电势、降低的暗电流和减少的载流子复合。由此产生的不含 SnF ₂和富含SnI _{2的 TPSCs 添加了 EDAI 2}实现了 10.0% 的稳态效率，这是 SnF _{2中最高的功率转换效率之一}-free TPSCs，以及显着提高的光稳定性。这项工作突出了添加剂在 TPSC 中的关键作用，并提供了一种制造高效稳定的低毒无铅钙钛矿太阳能电池的有效策略。