Vacuum-assisted technology, favored for its low cost, environmental friendliness, and scalability, is widely used in perovskite solar cells and is a preferred choice for commercialized production. However, strong solvent extraction at the interface between the wet film and vacuum causes a thin perovskite film at the top surface and residual solvent at the buried interface, which results in film stratification and buried voids. Consequently, the efficiency of vacuum-assisted Sn-Pb perovskite solar cells remains below 20%. Herein, we propose a light radiation annealing technique with rapid top-down heating to achieve unidirectional nucleation and growth, which effectively suppresses film stratification and buried voids. This approach yields Sn-Pb perovskite films with a more uniform composition and fewer defects. Based on the optimized films, we achieve a record efficiency of 22.31% among all the vacuum-assisted Sn-Pb perovskite solar cells. Moreover, we obtain an impressive efficiency of 27.62% for all-perovskite tandem solar cells.

中文翻译：

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光辐射退火可实现真空辅助 Sn-Pb 钙钛矿的单向结晶，用于高效的串联太阳能电池


真空辅助技术因其低成本、环境友好和可扩展性而受到青睐，广泛用于钙钛矿太阳能电池，是商业化生产的首选。然而，湿膜和真空界面处的强溶剂萃取导致顶面形成薄钙钛矿膜，埋藏界面处残留溶剂，从而导致薄膜分层和埋藏空隙。因此，真空辅助 Sn-Pb 钙钛矿太阳能电池的效率保持在 20% 以下。在此，我们提出了一种光辐射退火技术，采用快速自上而下的加热实现单向成核和生长，有效抑制薄膜分层和埋藏空隙。这种方法产生的 Sn-Pb 钙钛矿薄膜具有更均匀的成分和更少的缺陷。基于优化的薄膜，我们在所有真空辅助 Sn-Pb 钙钛矿太阳能电池中实现了创纪录的 22.31% 的效率。此外，我们获得了令人印象深刻的 27.62% 的全钙钛矿叠层太阳能电池效率。