The defects (e.g., I₂, anion, and cation vacancies) in the perovskite films are detrimental to the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). Herein, a multifunctional additive molecule 4-fluorophenylhydrazine hydrochloride (denoted as 4F-PHCl) is reported, which can improve perovskite crystallization, passivate film defects, and enhance film moisture stability, finally leading to the simultaneous increase in PCE and stability. It is revealed that the hydrazine functional group can effectively reduce the I₂ defects back to I^-. In addition, the hydrazinium contained cations and chloride anions can passivate the cationic defects (like anion vacancies) and anionic defects (like cation vacancies), respectively. The hydrophobic fluorinated benzene ring should be mainly responsible for the enhanced moisture stability of films and devices. As a result, the 4F-PHCl-modified device achieves a promising efficiency of 21.80% along with a high open-circuit voltage of 1172 mV and exhibits excellent long-term ambient stability. A guide for developing multifunctional additive molecules for the simultaneous enhancement of efficiency and stability is provided.

中文翻译：

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用于高效稳定钙钛矿太阳能电池的多功能还原分子调制器

钙钛矿薄膜中的缺陷（例如，I ₂、阴离子和阳离子空位）不利于钙钛矿太阳能电池（PSC）的功率转换效率（PCE）和稳定性。在此，报道了一种多功能添加剂分子 4-氟苯肼盐酸盐（记为 4F-PHCl），它可以改善钙钛矿结晶、钝化薄膜缺陷、增强薄膜水分稳定性，最终导致 PCE 和稳定性同时增加。结果表明，肼官能团可以有效地将I ₂缺陷还原为I ^-. 此外，含有阳离子和氯阴离子的肼可以分别钝化阳离子缺陷（如阴离子空位）和阴离子缺陷（如阳离子空位）。疏水性氟化苯环应主要负责提高薄膜和器件的水分稳定性。结果，4F-PHCl 修饰的器件实现了 21.80% 的有希望的效率以及 1172 mV 的高开路电压，并表现出优异的长期环境稳定性。提供了开发多功能添加剂分子以同时提高效率和稳定性的指南。