Das Antika, Ghosal Supriya, Marjit Kritiman, Pati Swapan K, Patra Amitava
School of Materials Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
Theoretical Sciences Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore 560064, India.
J Phys Chem Lett. 2024 Aug 8;15(31):7822-7831. doi: 10.1021/acs.jpclett.4c01837. Epub 2024 Jul 25.
Chiral lead halide perovskite (LHP) nanocrystals (NCs) have been attracting considerable interest for circularly polarized luminescence (CPL)-based optoelectronic applications. This study combined experimental and computational analyses to investigate how the dimensionality of 3D (cubic) to 0D (quantum dots) influences the tunable chiral emission of CsPbBr LHP NCs. The circular dichroism (CD) spectra have a significant blue shift from 508 to 406 nm. The dissymmetry factors for CD () change from ±2.5 × 10 to ±7.5 × 10 as dimensionality varies from 3D to 0D in the presence of the chiral molecule (cyclohexylethylamine, CHEA). A significant luminescence dissymmetry factor () of ±5.6 × 10 is observed in the 0D CsPbBr NCs. Theoretical calculations using structural distortion parameters, the extent of charge transfer, and electrostatic potential profiles have revealed that the most significant enhancement of the chirality transfer occurs from the CHEA molecules to 0D NCs, and the order of chirality transfer from CHEA to CsPbBr NCs is 0D (quantum dots) > 2D (nanoplatelet) > 3D (cubic).
手性卤化铅钙钛矿（LHP）纳米晶体（NCs）因其基于圆偏振发光（CPL）的光电应用而备受关注。本研究结合实验和计算分析，探究了从三维（立方）到零维（量子点）的维度变化如何影响CsPbBr LHP NCs的可调谐手性发射。圆二色性（CD）光谱有从508纳米到406纳米的显著蓝移。在手性分子（环己基乙胺，CHEA）存在的情况下，随着维度从三维变为零维，CD的不对称因子（）从±2.5×10变为±7.5×10。在零维CsPbBr NCs中观察到显著的发光不对称因子（）为±5.6×10。使用结构畸变参数、电荷转移程度和静电势分布进行的理论计算表明，手性转移的最显著增强发生在从CHEA分子到零维NCs的过程中，并且从CHEA到手性CsPbBr NCs的手性转移顺序为零维（量子点）>二维（纳米片）>三维（立方）。
