Quasi-2D metal-halide perovskites with Ruddlesden–Popper structures have shown promising stability due to the protective effects of the intercalating organic cations. However, a systematic study of the effect of intercalating organic cations on stability has rarely been reported. Here we use a high-throughput-robot platform to fabricate over 300 perovskite films and study the effect of cations and their concentrations on the thermal stability of perovskite films. We find that approximately 20–25 mol % of intercalating organic cations into MAPbI₃ (nominal n = 4/5) can maximize the film stability, while higher/lower concentrations lead to inferior stability, which is termed stability bowing in analogy to band-gap bowing. A model with two competitive effects of the intercalating organic cation (better protection vs more defects) is proposed to rationalize this behavior. We anticipate this work to provide new insights into the stability of quasi-2D perovskites.

中文翻译：

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准二维金属卤化物钙钛矿中插层有机阳离子诱导的稳定性弯曲

由于嵌入有机阳离子的保护作用，具有 Ruddlesden-Popper 结构的准二维金属卤化物钙钛矿已显示出良好的稳定性。然而，很少有关于嵌入有机阳离子对稳定性影响的系统研究报道。在这里，我们使用高通量机器人平台制造了 300 多个钙钛矿薄膜，并研究了阳离子及其浓度对钙钛矿薄膜热稳定性的影响。我们发现大约 20-25 mol% 的有机阳离子嵌入 MAPbI ₃（标称n= 4/5）可以最大限度地提高薄膜的稳定性，而较高/较低的浓度会导致较差的稳定性，这被称为类似于带隙弯曲的稳定性弯曲。提出了一种具有嵌入有机阳离子的两种竞争效应（更好的保护与更多的缺陷）的模型来合理化这种行为。我们预计这项工作将为准二维钙钛矿的稳定性提供新的见解。