近日，南方科技大学权泽卫团队实现了通过增强八面体畸变增强手性杂化金属卤化物的二次谐波产生和圆偏振发光。2025年6月2日出版的《德国应用化学》杂志发表了这项成果。

手性杂化金属卤化物（HMHs）以其非中心对称的晶体结构和优异的光物理性质为特征，在二阶非线性和线性光学中具有广阔的应用前景，包括二次谐波发生（SHG）和圆偏振发光（CPL）。然而，由于这些性质的独特结构和电子要求，同时具有强SHG响应和高效CPL的手性HMH仍然是一个挑战。

研究组报告了一种无机八面体中的卤素替代策略，可以调节晶体结构，同时增强SHG和CPL性能。合成了三对手性Sb基HMH：（R/S-MBA）₂IASbBr₆（MBA=α-甲基苄基铵，IA=咪唑，缩写为R/S-SbBr₆）、（R/S-MMA）₂IASbBr_2.8Cl_3.2（R/S-SbBr_2.8Cl_3.2）和（R/S-MAB）₂IASbCl₆（R/S-SbCl₆）。 

从R/S-SbBr₆到R/S-SbCl₆的卤素逐渐取代显著增强了无机八面体的结构手性，导致1.4×KDP的强SHG响应强度和3.82×10^-2的高发光不对称因子。SHG和CPL的组合性能优于之前的手性HMH。实验结果和理论计算表明，这些增强源于卤素取代引起的八面体畸变逐渐增加。这项工作建立了一种结构优化策略，用于推进手性HMH中的高性能SHG和CPL，为其更广泛的光子应用铺平了道路。

附：英文原文

Title: Simultaneous Boosting of Second Harmonic Generation and Circularly Polarized Luminescence in Chiral Hybrid Metal Halides through Enhanced Octahedral Distortion

Author: Yulian Liu, Xi Zhang, Xiaofan Xu, Junfeng Dai, Zewei Quan

Issue&Volume: 2025-06-02

Abstract: Chiral hybrid metal halides (HMHs), characterized by their non-centrosymmetric crystal structures and exceptional photophysical properties, are promising for second-order nonlinear and linear optics, including second harmonic generation (SHG) and circularly polarized luminescence (CPL). However, chiral HMHs with simultaneously strong SHG response and efficient CPL still presents a challenge, due to the distinct structural and electronic requirements of these properties. Here, we report a halogen substitution strategy within inorganic octahedra to modulate the crystal structure and simultaneously enhance both SHG and CPL properties. Three pairs of chiral Sb-based HMHs are synthesized: (R/S-MBA)2IASbBr6 (MBA = α-methylbenzylammonium, IA = imidazole, abbreviated as R/S-SbBr6), (R/S-MBA)2IASbBr2.8Cl3.2 (R/S-SbBr2.8Cl3.2), and (R/S-MBA)2IASbCl6 (R/S-SbCl6). The gradual halogen substitution from R/S-SbBr6 to R/S-SbCl6 significantly enhances the structural chirality of inorganic octahedra, resulting in a strong SHG response intensity of 1.4 × KDP and a high luminescence dissymmetry factor of 3.82 × 10-2. The combination of SHG and CPL performance outperforms that of previous chiral HMHs. Experimental results and theoretical calculations indicate that these enhancements originate from gradually increased octahedral distortions induced by halogen substitution. This work establishes a structural optimization strategy for advancing high-performance SHG and CPL in chiral HMHs, paving the way for their broader photonic applications.

DOI: 10.1002/anie.202510579

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202510579