The performance of narrow-bandgap (NBG) perovskite solar cells (PSCs) is limited by the severe nonradiative recombination and carrier transport barrier at the electron selective interface. Here, we reveal the importance of the molecular orientation for effective defect passivation and protection for Sn²⁺ at the perovskite/C₆₀ interface. We constructed an internally self-anchored dual-passivation (ISADP) layer, where the orientation of PCBM can be significantly enhanced by the interaction between ammonium and carbonyl groups. It can facilitate the contact with C₆₀ and minimize the nonradiative energy loss at the electron transport interface. This strategy remarkably enhances the FF of NBG PSCs, from 77.45% to 82.88%, and the power conversion efficiency (PCE) from 20.67% to 24.02%. Moreover, monolithic all-perovskite TSCs exhibit a high certified PCE (under reverse scan) of 28.12% and a record FF of 84.25%. This work opens up a new pathway for enhancing the performance of monolithic all-perovskite TSCs.

中文翻译：

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取向增强夹层可实现高效的 Sn-Pb 二元钙钛矿太阳能电池和具有高填充因子的全钙钛矿叠层太阳能电池


窄带隙 （NBG） 钙钛矿太阳能电池 （PSC） 的性能受到电子选择性界面处严重的非辐射复合和载流子传输势垒的限制。在这里，我们揭示了分子取向对于钙钛矿/C₆₀ 界面处有效缺陷钝化和保护 Sn²⁺ 的重要性。我们构建了一个内部自锚定双钝化 （ISADP） 层，其中 PCBM 的取向可以通过铵和羰基之间的相互作用显着增强。它可以促进与 C₆₀ 的接触，并最大限度地减少电子传输界面处的非辐射能量损失。该策略显著提高了 NBG PSCs 的 FF 从 77.45% 提高到 82.88%，功率转换效率 （PCE） 从 20.67% 提高到 24.02%。此外，单片全钙钛矿 TSC 表现出 28.12% 的高认证 PCE（反向扫描下）和创纪录的 84.25% 的 FF。这项工作为提高单片全钙钛矿 TSC 的性能开辟了一条新途径。