High efficiency and good stability are the challenges for perovskite solar cells (PSCs) toward commercialization. However, the intrinsic high defect density and internal nonradiative recombination of perovskite (PVK) limit its development. In this work, a facile additive strategy is devised by introducing bifunctional guanidine sulfamate (GuaSM; CH₆N₃⁺, Gua⁺; H₂N−SO₃⁻, SM⁻) into PVK. The size of Gua⁺ ion is suitable with Pb(BrI)₂ cavity relatively, so it can participate in the formation of low‐dimensional PVK when mixed with Pb(BrI)₂. The O and N atoms of SM⁻ can coordinate with Pb²⁺. The synergistic effect of the anions and cations effectively reduces the trap density and the recombination in PVK, so that it can improve the efficiency and stability of PSCs. At an optimal concentration of GuaSM (2 mol%), the PSC presents a champion power conversion efficiency of 21.66% and a remarkably improved stability and hysteresis. The results provide a novel strategy for highly efficient and stable PSCs by bifunctional additive.

中文翻译：

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双功能氨基磺酸胍对高效稳定钙钛矿太阳能电池的加性工程

钙钛矿太阳能电池（PSC）的商业化挑战是高效率和良好的稳定性。但是，钙钛矿（PVK）固有的高缺陷密度和内部非辐射重组限制了其发展。在这项工作中，一个浅显的添加剂的策略是通过引入双官能氨基磺酸胍设计（GuaSM; CH ₆ Ñ ₃ ⁺，卦⁺ ; H ₂ N-二SO ₃ ^-，SM ^- ）插入PVK。Gua ⁺离子的大小相对适合Pb（BrI）₂腔，因此当与Pb（BrI）₂混合时它可以参与低维PVK的形成。SM中的O和N原子^-可以与Pb ²⁺配合使用。阴离子和阳离子的协同作用有效地降低了PVK中的陷阱密度和重组，从而提高了PSC的效率和稳定性。在GuaSM（2 mol％）的最佳浓度下，PSC的功率转换效率为21.66％，稳定性和滞后性显着提高。结果为双功能添加剂提供了高效，稳定的PSC的新策略。