Defect passivation with organic molecules is a significant strategy to improve perovskite solar cells (PSCs). However, because of carrier extraction and recombination in the bottom of the perovskite film, solar cell improvement is hindered. In this work, molecules of sodium 3-oxo-3H-spiro [isobenzofuran-1,9′-xanthene]-3′,6′-bis(olate) (SSB) were pre-buried into the SnO₂ electron transport layer (ETL), which resulted in modification of the SnO₂ and perovskite interface. This SSB molecular treatment improved the quality of the SnO₂ film. Moreover, the SSB molecule realized interfacial interaction with SnO₂ and perovskite, and substantially reduced the trap state density and enhanced charge extraction. As a result, the photovoltaic performances of the PSCs with the SSB devices improved, achieving an impressive efficiency of up to 22.64%. Additionally, the SSB devices without encapsulation demonstrated enhanced stability in air (at approximately 25 °C at approximately 30% humidity) and in an N₂ environment under continuous illumination.

中文翻译：

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用于高效钙钛矿太阳能电池的小分子掺入 SnO2 层

用有机分子进行缺陷钝化是改善钙钛矿太阳能电池（PSC）的重要策略。然而，由于钙钛矿薄膜底部的载流子提取和复合，太阳能电池的改进受到阻碍。在这项工作中，3-氧代-3H-螺钠[异苯并呋喃-1,9'-呫吨]-3',6'-双(醇)钠(SSB)分子被预埋入SnO 2电子传输层_中( ETL），这导致 SnO ₂和钙钛矿界面的改性。_{这种SSB分子处理提高了SnO 2}薄膜的质量。此外，SSB分子实现了与SnO _{2的界面相互作用}和钙钛矿，并大大降低了陷阱态密度并增强了电荷提取。因此，采用 SSB 器件的 PSC 的光伏性能得到了改善，实现了高达 22.64% 的令人印象深刻的效率。此外，未封装的 SSB 器件在空气（约 25 °C、约 30% 湿度）和连续照明下的 N ₂环境中表现出增强的稳定性。