In perovskite solar cells (PSCs), the interfaces between perovskite film and charge transport layers have an enormous influence on the device performance and stability. Recently, it has been proven that the surface defect passivation of perovskite layer is an effective strategy to improve the device efficiency. Herein, an organic ammonium salt benzyltriethylammonium chloride ([BZTAm]Cl) is used as an ultra‐thin modification layer in perovskite films in MAPbI₃ PSCs for passivating the surface defects. The obtained results demonstrate that the [BZTAm]Cl modifier improves the crystallization/morphology of perovskite film and effectively aligns the energy levels with the corresponding charge‐transporting layers, suppressing the nonradiative recombination and reducing the trap state density. As a result, a champion device efficiency of 20.45% is achieved for optimized concentration of [BZTAm]Cl in comparison with 17.87% for the control device. Moreover, the unencapsulated device presents a good long‐term stability after aging in an ambient environment with 40–50% relative humidity conditions for 30 days.

中文翻译：

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用氯化有机盐检查界面缺陷钝化的高效稳定钙钛矿太阳能电池

在钙钛矿太阳能电池（PSC）中，钙钛矿薄膜和电荷传输层之间的界面对器件性能和稳定性有很大影响。最近，已经证明钙钛矿层的表面缺陷钝化是提高器件效率的有效策略。本文将有机铵盐苄基三乙基氯化铵（[BZTAm] Cl）用作MAPbI ₃中钙钛矿薄膜的超薄改性层。用于钝化表面缺陷的PSC。获得的结果表明，[BZTAm] Cl改性剂改善了钙钛矿薄膜的结晶/形貌，并使能级与相应的电荷传输层有效对齐，从而抑制了非辐射复合并降低了陷阱态密度。结果，相比于控制装置的17.87％，最佳浓度的[BZTAm] Cl达到了20.45％的最佳装置效率。此外，未封装的设备在相对湿度为40％至50％的环境中老化30天后，具有良好的长期稳定性。