Interface engineering has become one of the important subjects in developing efficient and stable perovskite solar cells (PSCs). Herein, an interfacial molecular linker, chloroformamidine hydrochloride (CFA), is introduced to modify the properties of electron transport layers (ETLs) and modulate the interaction between the ETL and perovskite (PVK) layer via coordination/electrostatic coupling. It is found that the CFA molecular linker can passivate the oxygen vacancies/interfacial defects of SnO₂ and construct an improved energetic alignment between the ETL and PVK layer. Consequently, a power conversion efficiency (PCE) of 23.47% with an open-circuit voltage (V_OC) of 1.17 V for the target device is achieved. Moreover, unencapsulated PSCs based on CFA-modified SnO₂ (CFA@SnO₂) ETLs show enhanced thermal and moisture stability compared with PSCs without CFA modification. This work provides a feasible strategy to tune the interface between the ETL and PVK for efficient and stable PSCs.

中文翻译：

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氯甲脒盐酸盐作为高效稳定钙钛矿太阳能电池的分子连接剂

界面工程已成为开发高效稳定的钙钛矿太阳能电池（PSC）的重要课题之一。在此，引入界面分子连接剂氯甲脒盐酸盐 (CFA) 来改变电子传输层 (ETL) 的性质，并通过配位/静电耦合调节 ETL 和钙钛矿 (PVK) 层之间的相互作用。结果发现，CFA 分子连接剂可以钝化 SnO ₂的氧空位/界面缺陷，并在 ETL 和 PVK 层之间构建改进的能量排列。因此，功率转换效率 (PCE) 为 23.47%，开路电压 ( V _OC）为目标设备实现了 1.17 V。此外，与未经 CFA 改性的 PSC 相比，基于 CFA 改性 SnO ₂ (CFA@SnO _{2 ) ETL 的未封装 PSC 显示出更高的热稳定性和湿度稳定性。}这项工作提供了一种可行的策略来调整 ETL 和 PVK 之间的接口，以实现高效稳定的 PSC。