Harmful defects are typically major performance and stability degrading factors in perovskite solar cells (PSCs). In order to prevent defect formation and ion migration, some small molecule additives are often used in PSCs, which, however, are highly volatile and very likely to drift. In this work, an amphiphilic polymer, p(HEMA-co-DEAMA), is synthesized and doped into organic salt solution. Through Lewis base coordination and hydrogen bonding, it can be chemically bonded to a perovskite. Further analysis reveals that trap density is significantly reduced after simple treatment with p(HEMA-co-DEAMA), suppressing charge recombination and boosting the power conversion efficiency (PCE) of PSCs. Moreover, the ordered long chain structure of p(HEMA-co-DEAMA) forms a gridlike crystal, which stitches the grain boundaries and thus modulates the growth of perovskite crystals therein. Importantly, the exposure of the long alkyl chains on p(HEMA-co-DEAMA) also provides a hydrophobic coating, which protects the perovskite film from environmental humidity and further enhances the operation stability. Therefore, the unpackaged devices modified with p(HEMA-co-DEAMA) exhibit excellent stability with retaining more than 90% of the original PCE when stored for 1000 h in an air environment, indicating the viability of our strategies.

中文翻译：

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两亲性聚合物添加剂可抑制电荷复合的钙钛矿太阳能电池的缺陷钝化

有害缺陷通常是钙钛矿太阳能电池（PSC）性能和稳定性的主要降低因素。为了防止缺陷形成和离子迁移，PSC中经常使用一些小分子添加剂，但这些添加剂具有很高的挥发性，很容易漂移。在这项工作中，合成了一种两亲性聚合物p(HEMA- co -DEAMA)，并将其掺杂到有机盐溶液中。通过路易斯碱配位和氢键，它可以化学键合到钙钛矿上。进一步分析表明，经过p(HEMA- co -DEAMA)简单处理后，陷阱密度显着降低，抑制了电荷复合并提高了PSC的功率转换效率（PCE）。此外，p(HEMA -co -DEAMA)的有序长链结构形成网格状晶体，其缝合晶界，从而调节其中钙钛矿晶体的生长。重要的是，p(HEMA- co -DEAMA)上长烷基链的暴露还提供了疏水涂层，可以保护钙钛矿薄膜免受环境湿度的影响，并进一步增强操作稳定性。因此，用p(HEMA- co -DEAMA)修饰的未封装器件表现出优异的稳定性，在空气环境中储存1000小时时保留了90%以上的原始PCE，表明我们的策略的可行性。