The inherent structural flexibility and chiroptical activity of 2D chiral perovskites make them promising for the nonlinear optical (NLO) application. A comprehensive understanding of the second‐harmonic generation (SHG) mechanism in 2D chiral perovskites is essential for developing NLO devices. However, the rational design of 2D chiral perovskite structures to regulate SHG properties remains challenging. Herein, to regulate SHG response, an achiral organic spacer cation alloying strategy is employed to construct a series of 2D chiral perovskites. Through the measurement of temperature‐dependent photoluminescence (PL) spectra, it is revealed that the material design strategy can effectively modulating self‐trapped exciton (STE) emission. More importantly, it is confirmed that there is a competitive relationship between STE emission and SHG in 2D chiral perovskites. Meanwhile, the microscopic imaging of circularly polarized‐SHG is demonstrated in chiral perovskites. This work will not only advance the understanding of the SHG mechanism in 2D chiral perovskites but also provide inspiration for the rational design and synthesis of perovskites for NLO devices.

中文翻译：

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通过非手性有机间隔阳离子合金化策略调控二维手性钙钛矿中的二次谐波产生


2D 手性钙钛矿固有的结构灵活性和手性光学活性使其在非线性光学 （NLO） 应用中大有希望。全面了解 2D 手性钙钛矿中的二次谐波产生 （SHG） 机制对于开发 NLO 器件至关重要。然而，用于调节 SHG 特性的 2D 手性钙钛矿结构的合理设计仍然具有挑战性。在此，为了调节 SHG 响应，采用非手性有机间隔阳离子合金化策略构建一系列 2D 手性钙钛矿。通过对温度依赖性光致发光 （PL） 光谱的测量，揭示了材料设计策略可以有效地调节自捕获激子 （STE） 发射。更重要的是，证实了 STE 发射和 SHG 在 2D 手性钙钛矿中存在竞争关系。同时，圆极化 SHG 的显微成像在手性钙钛矿中得到证明。这项工作不仅将促进对二维手性钙钛矿中 SHG 机制的理解，还将为 NLO 器件钙钛矿的合理设计和合成提供灵感。