Optically Active CdSe-Dot/CdS-Rod Nanocrystals with Induced Chirality and Circularly Polarized Luminescence
Optically Active CdSe-Dot/CdS-Rod Nanocrystals with Induced Chirality and Circularly Polarized Luminescence
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DOI：
10.1021/acsnano.8b00112
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发表时间：
2018-06-01
期刊：
影响因子：
17.1
通讯作者：
He, Tingchao
中科院分区：
文献类型：
--
作者：
Cheng, Jiaji;Hao, Junjie;He, Tingchao
由于半导体纳米晶体具有可调谐的光学特性，其配体诱导手性一直受到人们的关注。在CdX （X = S, Se, Te）纳米材料及其杂化体中观察到诱导圆二色性（CD），但这些荧光纳米材料的圆偏振发光（CPL）很少报道。在此，我们成功制备了L-和d -半胱氨酸覆盖的CdSe-dot/ cds棒（DRs），具有可调谐的CD和CPL行为，最大各向异性因子（g(lum)）为4.66 X 10（-4）。CD和CPL活性对CD壳与CdSe核的相对吸收比敏感，表明CD和CPL各向异性g因子在一定程度上增加，导致壳核吸收比减小。此外，还研究了手性半胱氨酸与DRs的摩尔比。水溶液中过量的半胱氨酸分子不但没有增强手性分子与dr之间的手性相互作用，反而抑制了CD和CPL的活性。这种具有手性和发射性的纳米材料为合理设计具有手性的半导体纳米材料提供了理想的平台。
Ligand-induced chirality in semiconductor nanocrystals (NCs) has attracted attention because of the tunable optical properties of the NCs. Induced circular dichroism (CD) has been observed in CdX (X = S, Se, Te) NCs and their hybrids, but circularly polarized luminescence (CPL) in these fluorescent nanomaterials has been seldom reported. Herein, we describe the successful preparation of L- and D-cysteine-capped CdSe-dot/CdS-rods (DRs) with tunable CD and CPL behaviors and a maximum anisotropic factor (g(lum)) of 4.66 X 10(-4). The observed CD and CPL activities are sensitive to the relative absorption ratio of the CdS shell to the CdSe core, suggesting that the anisotropic g-factors in both CD and CPL increase to some extent for a smaller shell-to-core absorption ratio. In addition, the molar ratio of chiral cysteine to the DRs is investigated. Instead of enhancing the chiral interactions between the chiral molecules and DRs, an excess of cysteine molecules in aqueous solution inhibits both the CD and CPL activities. Such chiral and emissive NCs provide an ideal platform for the rational design of semiconductor nanomaterials with chiroptical properties.