All-inorganic perovskite solar cells (PVSCs) have drawn increasing attention because of their outstanding thermal stability. However, their performance is still inferior than the typical organic-inorganic counterparts, especially for the devices with p-i-n configuration. Herein, we successfully employ a Lewis base small molecule to passivate the inorganic perovskite film, and its derived PVSCs achieved a champion efficiency of 16.1% and a certificated efficiency of 15.6% with improved photostability, representing the most efficient inverted all-inorganic PVSCs to date. Our studies reveal that the nitrile (C-N) groups on the small molecule effectively reduce the trap density of the perovskite film and thus significantly suppresses the non-radiative recombination in the derived PVSC by passivating the Pb-exposed surface, resulting in an improved open-circuit voltage from 1.10 V to 1.16 V after passivation. This work provides an insight in the design of functional interlayers for improving efficiencies and stability of all-inorganic PVSCs.

中文翻译：

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高效的全无机钙钛矿太阳能电池，路易斯碱抑制了非辐射复合。

由于其出色的热稳定性，全无机钙钛矿太阳能电池（PVSC）引起了越来越多的关注。但是，它们的性能仍然不如典型的有机-无机同类产品，特别是对于具有引脚配置的设备。在本文中，我们成功地使用了路易斯基础小分子对无机钙钛矿薄膜进行钝化，其衍生的PVSC的冠军效率为16.1％，经认证的效率为15.6％，且光稳定性得到改善，代表了迄今为止最有效的倒置全无机PVSC 。我们的研究表明，小分子上的腈（CN）基团有效地降低了钙钛矿薄膜的陷阱密度，从而通过钝化暴露于Pb的表面显着抑制了衍生的PVSC中的非辐射复合，钝化后，开路电压从1.10 V提高到1.16V。这项工作为功能性中间层的设计提供了见识，以提高全无机PVSC的效率和稳定性。