Suppressing nonradiative recombination and releasing residual strain are prerequisites to improving the efficiency and stability of perovskite solar cells (PSCs). Here, long-chain polyacrylic acid (PAA) is used to reinforce SnO₂ film and passivate SnO₂ defects, forming a structure similar to “reinforced concrete” with high tensile strength and fewer microcracks. Simultaneously, PAA is also introduced to the SnO₂/perovskite interface as a “buffer spring” to release residual strain, which also acts as a “dual-side passivation interlayer” to passivate the oxygen vacancies of SnO₂ and Pb dangling bonds in halide perovskites. As a result, the best inorganic CsPbBr₃ PSC achieves a champion power conversion efficiency of 10.83% with an ultrahigh open-circuit voltage of 1.674 V. The unencapsulated PSC shows excellent stability under 80% relative humidity and 80°C over 120 days.

中文翻译：

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用于高效无机钙钛矿太阳能电池的增强 SnO2 拉伸强度和“缓冲弹簧”界面

抑制非辐射复合和释放残余应变是提高钙钛矿太阳能电池（PSC）效率和稳定性的先决条件。这里，长链聚丙烯酸（PAA）用于增强SnO ₂薄膜并钝化SnO ₂缺陷，形成类似“钢筋混凝土”的结构，具有高拉伸强度和更少的微裂纹。同时，PAA也被引入SnO ₂ /钙钛矿界面作为“缓冲弹簧”释放残余应变，同时也作为“双面钝化中间层”钝化卤化物中SnO ₂和Pb悬键的氧空位钙钛矿。结果，最好的无机 CsPbBr ₃ PSC 实现了 10.83% 的冠军功率转换效率和 1.674 V 的超高开路电压。未封装的 PSC 在 80% 相对湿度和 80°C 下 120 天表现出出色的稳定性。