Sun Meng-En, Wang Fei, He Manman, Yang Ya-Ni, Yang Ji-Kun, Zhu Meng-Jie, Wan Qiu-Yang, Chen Gaosong, Wang Yonggang, Fu Yongping, Li Qi, Wang Zhenling, Jiang Lei, Wu Yuchen, Zang Shuang-Quan
Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
Henan International Joint Laboratory of Rare Earth Composite Materials, College of Material Engineering, Henan University of Engineering, Zhengzhou 451191, China.
J Am Chem Soc. 2025 Mar 26;147(12):10706-10714. doi: 10.1021/jacs.5c01503. Epub 2025 Mar 11.
Achieving ultrahigh-color-purity circularly polarized luminescence (CPL) in low-dimensional chiral perovskites is challenging due to strong electron-phonon coupling caused by lead halide octahedral distortion. Herein, the circularly polarized piezoluminescence behaviors of six novel chiral perovskites, (/-3-XPEA)PbBr (PEA = phenethylamine; X = F, Cl, Br), were systematically investigated. Upon compression, (/-3-ClPEA)PbBr exhibits significant piezofluorochromic behaviors, transforming from yellow CPL to ultrahigh-color-purity deep-blue CPL. At 2.5 GPa, the deep-blue CPL intensity increases by an order of magnitude and its luminescence asymmetry factors () are amplified from the initial ±0.03 to ±0.1. (/-3-BrPEA)PbBr presents a similar piezochromic response, realizing deep-blue CPL at 1.7 GPa, while (/-3-FPEA)PbBr retains a yellow CPL under high pressure. High-pressure structural characterization and theoretical calculations confirm that pressure-enhanced halogen bonds reduce the penetration depth of /-3-BrPEA and /-3-ClPEA into the [PbBr] frameworks, significantly suppressing electron-phonon coupling and increasing magnetic transition dipole moment in (/-3-BrPEA)PbBr and (/-3-ClPEA)PbBr, which are responsible for the ultrahigh-purity deep-blue CPL and chirality amplification, respectively.
由于卤化铅八面体畸变引起的强电子 - 声子耦合，在低维手性钙钛矿中实现超高色纯度圆偏振发光（CPL）具有挑战性。在此，系统研究了六种新型手性钙钛矿（/-3-XPEA）PbBr（PEA = 苯乙胺；X = F、Cl、Br）的圆偏振压致发光行为。压缩时，（/-3-ClPEA）PbBr表现出显著的压致荧光变色行为，从黄色CPL转变为超高色纯度深蓝色CPL。在2.5 GPa时，深蓝色CPL强度增加一个数量级，其发光不对称因子（）从初始的±0.03放大到±0.1。（/-3-BrPEA）PbBr呈现类似的压致变色响应，在1.7 GPa时实现深蓝色CPL，而（/-3-FPEA）PbBr在高压下保持黄色CPL。高压结构表征和理论计算证实，压力增强的氢键减少了/-3-BrPEA和/-3-ClPEA进入[PbBr]框架的穿透深度，显著抑制了（/-3-BrPEA）PbBr和（/-3-ClPEA）PbBr中的电子 - 声子耦合并增加了磁跃迁偶极矩，它们分别导致了超高纯度深蓝色CPL和手性放大。
