Simultaneously improving device efficiency and stability is the most important issue in perovskite solar cell (PSC) research. Here, we strategically introduce a multi-functional interface layer (MFIL) with integrated roles of: (1) electron transport, (2) moisture barrier, (3) near-infrared photocurrent enhancement, (4) trap passivation, and (5) ion migration suppression to enhance the device performance. The narrow-band-gap non-fullerene acceptor, Y6, was screened out to replace the most commonly used PCBM in the inverted PSCs. A significantly improved power conversion efficiency of 21.0% was achieved, along with a remarkable stability (up to 1,700 h) without encapsulation under various external stimuli (light, heat, and moisture). Furthermore, systematic studies of the molecular orientation or passivation and the charge carrier dynamics at the interface between perovskite and MFIL were presented. These results offer deep insights for designing advanced interlayers and establish the correlations between molecular orientation, interface molecular bonding, trap state density, non-radiation recombination, and the device performance.

同时提高器件效率和稳定性是钙钛矿太阳能电池（PSC）研究中最重要的问题。在这里，我们从战略上引入了多功能界面层（MFIL），其集成作用包括：（1）电子传输，（2）防潮层，（3）近红外光电流增强，（4）陷阱钝化和（5）抑制离子迁移，以增强器件性能。筛选出窄带隙非富勒烯受体Y6，以替代倒置PSC中最常用的PCBM。在各种外部刺激（光，热和湿气）下无需封装的情况下，功率转换效率显着提高，达到21.0％，并具有显着的稳定性（长达1,700 h）。此外，提出了钙钛矿与MFIL界面上分子取向或钝化以及电荷载流子动力学的系统研究。这些结果为设计高级中间层提供了深刻的见识，并建立了分子取向，界面分子键，陷阱态密度，非辐射重组和器件性能之间的相关性。