Understanding the structure–chiroptical activity relationship in chiral perovskites is of great significance as it provides a pathway to control light–matter interactions. Although many reports have shown various chiral structures with distinctive chiroptical responses, a clear structure–property relationship is still missing, partially stemming from the poor understanding of the optical activity mechanism. For instance, it remains unclear if and how the chiroptical activity is related to exciton spin splitting. Herein, we used magnetic circular dichroism to probe the exciton spin splitting in a series of chiral 2D perovskites. Our results show that the anisotropy factor of circular dichroism is indeed proportional to the exciton spin splitting energy, with larger splitting energy yielding larger anisotropy factors. Further structural analysis showed that the splitting energy is closely correlated with both the in-plane and out-of-plane distortion structural parameters of the inorganic lattice. Our work provides an important mechanistic understanding of chiroptical activity and establishes the structure–property relationship for 2D chiral perovskites.

中文翻译：

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破译手性 2D 钙钛矿手电活性的电子和结构起源


了解手性钙钛矿中的结构-手光活性关系具有重要意义，因为它提供了控制光-物质相互作用的途径。尽管许多报道显示了具有独特手性反应的各种手性结构，但仍然缺乏明确的结构-性质关系，部分原因是对光学活动机制的理解不足。例如，目前尚不清楚手性活动是否以及如何与激子自旋分裂相关。在此，我们使用磁性圆二色性来探测一系列手性 2D 钙钛矿中的激子自旋分裂。我们的结果表明，圆二色性的各向异性因子确实与激子自旋分裂能量成正比，分裂能量越大，产生越大的各向异性因子。进一步的结构分析表明，分裂能与无机晶格的面内和面外畸变结构参数密切相关。我们的工作提供了对手光学活性的重要机理理解，并建立了 2D 手性钙钛矿的结构-性质关系。