SnO₂ stands as a prominently employed material as electron transport layer (ETL) for perovskite solar cells (PSCs). Nevertheless, SnO₂ films prepared at low temperatures are accompanied by defects that will influent the transport of carriers at the interface, misalignment of energy levels, and the quality of thin perovskite film formation. Here, we introduce 4-aminobenzoic acid ethyl ester (4-AN), characterized by its carbonyl (C=O) and amino (-NH₂) groups, as a synergistic defect passivation agent on the surfaces of SnO₂ and perovskite films. This approach aims to enhance the electron transport properties of SnO₂. By optimizing the energy alignment between SnO₂ and perovskite, 4-AN facilitates more efficient extraction of interfacial carriers, while also promoting the crystalline quality of perovskite films and suppressing carrier recombination at the interface. The long alkyl chains at the end play an important role in relieving the interfacial contact and help to enhance the SnO₂/perovskite interfacial connection. Compared with pristine SnO₂, the PSCs based on 4-AN modified SnO₂ obtained an optimal efficiency of 21.83%, while the devices maintained 90% and 83% of their initial PCE after storage for 1000 h in an N₂ environment and humidity of 30-50%. This work provides valid insights for the development of novel interface modification materials.

中文翻译：

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具有协同改性 SnO2 的多功能有机分子用于高效钙钛矿太阳能电池


SnO₂ 是钙钛矿太阳能电池 （PSC） 的电子传输层 （ETL） 的重要应用材料。然而，在低温下制备的 SnO₂ 薄膜伴随着缺陷，这些缺陷会影响界面处载流子的传输、能级的错位以及钙钛矿薄膜形成的质量。在这里，我们介绍了 4-氨基苯甲酸乙酯 （4-AN），其特征是其羰基 （C=O） 和氨基 （-NH₂） 基团，作为 SnO₂ 和钙钛矿薄膜表面的协同缺陷钝化剂。这种方法旨在增强 SnO₂ 的电子传输特性。通过优化 SnO₂ 和钙钛矿之间的能量对准，4-AN 有助于更有效地提取界面载流子，同时还能提高钙钛矿薄膜的结晶质量并抑制界面处的载流子复合。末端的长烷基链在缓解界面接触方面起着重要作用，并有助于增强 SnO₂/钙钛矿界面连接。与原始 SnO₂ 相比，基于 4-AN 修饰的 SnO₂ 的 PSC 获得了 21.83% 的最佳效率，而在 N₂ 环境和 30-50% 的湿度下储存 1000 小时后，器件保持了 90% 和 83% 的初始 PCE。这项工作为新型界面修饰材料的开发提供了有效的见解。