Tremendous efforts have been dedicated toward minimizing the open-circuit voltage deficits on perovskite solar cells (PSCs), and the fill factors are still relatively low. This hinders their further application in large scalable modules. Herein, we employ a newly designed ammonium salt, cyclohexylethylammonium iodide (CEAI), for interfacial engineering between the perovskite and hole-transporting layer (HTL), which enhanced the fill factor to 82.6% and consequent PCE of 23.57% on the target device. This can be associated with a reduction of the trap-assisted recombination rate at the 3D perovskite surface, via formation of a 2D perovskite interlayer. Remarkably, the property of the 2D perovskite interlayer along with the cyclohexylethyl group introduced by CEAI treatment also determines a pronounced enhancement in the surface hydrophobicity, leading to an outstanding stability of over 96% remaining efficiency of the passivated devices under maximum power point tracking with one sun illumination under N₂ atmosphere at room temperature after 1500 h.

中文翻译：

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钙钛矿太阳能电池的界面钝化工程，具有超过 82% 的填充因子和出色的 nip 结构运行稳定性

一直致力于最大限度地减少钙钛矿太阳能电池 (PSC) 的开路电压不足，但填充因子仍然相对较低。这阻碍了它们在大型可扩展模块中的进一步应用。在此，我们采用新设计的铵盐环己基乙基碘化铵 (CEAI) 进行钙钛矿和空穴传输层 (HTL) 之间的界面工程，将目标器件的填充因子提高到 82.6%，从而使 PCE 提高到 23.57%。这可能与通过形成 2D 钙钛矿夹层降低 3D 钙钛矿表面的陷阱辅助复合率有关。值得注意的是，二维钙钛矿夹层的特性以及由 CEAI 处理引入的环己基乙基也决定了表面疏水性的显着增强，1500 小时后室温_{2 个}大气压。