Interfacial engineering is a highly effective strategy to improve device performance of perovskite solar cells (PSCs) by alleviating the defect-induced non-radiative recombination, while reports on defect passivation of the two-step processed perovskite films are quite limited to date. Herein, a new type of multifunctional molecule, 1-methanesulfonyl-piperazine (MP), is applied to modify the perovskite film that is fabricated via a two-step process. The introduction of MP passivation enables multiple bonding interactions with perovskite film, i.e., hydrogen bond, Pb-O and Pb-N dative bonds, resulting in significantly reduced trap density and effectively suppressed non-radiative recombination. Moreover, the MP-modified perovskite films show improved crystallinity with decreased PbI₂ residuals, which is conducive to both carrier transport and stability of the resultant devices. As a consequence, the MP-modified devices present an impressive power conversion efficiency (PCE) of 23.4% along with enhanced stability, e.g., the unencapsulated device retains 88% of its original PCE even subject to thermal aging at 85 ℃ for 600 h. This work opens up an avenue to explore functional materials for high-performance and long-term stable PSCs.

界面工程是通过减轻缺陷引起的非辐射复合来提高钙钛矿太阳能电池 (PSC) 器件性能的一种高效策略，而迄今为止关于两步处理钙钛矿薄膜缺陷钝化的报道非常有限。在这里，一种新型的多功能分子，1-甲磺酰基-哌嗪（MP），被应用于对通过两步法制备的钙钛矿薄膜进行改性。MP钝化的引入使得与钙钛矿薄膜的多重键相互作用，即氢键、Pb-O和Pb-N配键，导致陷阱密度显着降低并有效抑制非辐射复合。此外，MP 改性的钙钛矿薄膜表现出更高的结晶度，同时降低了 PbI ₂残余物，这有利于载流子传输和所得器件的稳定性。因此，MP 改进的器件表现出令人印象深刻的 23.4% 的功率转换效率 (PCE) 以及增强的稳定性，例如，即使在 85 ℃ 下热老化 600 小时，未封装的器件仍保留其原始 PCE 的 88% 。这项工作为探索用于高性能和长期稳定 PSC 的功能材料开辟了道路。