Advanced Optical Materials
·
2021
·Vol. 9
·期 20
·2101142
·
IF 9.926
Junjie Hao,Fenghuan Zhao,Qiushi Wang,Jiaying Lin,Peixian Chen,Junzi Li,Dongxiang Zhang,Meijuan Chen,Peizhao Liu,Marie-Helene Delville,Tingchao He,Jiaji Cheng,Yiwen Li
Ligand-induced chirality in colloidal semiconductor nanocrystals attracts attention because of their tunable chiroptical properties. Here, the induced chirality and circularly polarized luminescence (CPL) are investigated as a function of the CdS shell growth in a range of 2D CdSe/CdS nanoplatelets (NPLs) capped with chiral ligands. Five samples of CdSe/CdS NPLs are synthesized by a one-pot approach to vary the island-like shell on a four-monolayer (4 ML) CdSe NPLs core, which effectively reduces the interfacial strain energy. The successful preparation of L-/D-Cysteine-capped CdSe/CdS NPLs with both tunable circular dichroism (CD) and CPL behaviors and a maximum anisotropic luminance factor ( g lum ) of 5.29 × 10 −4 is described. The induced chiroptical response shows a direct relationship with the formation of island-like shell in the first and second stages and shows a clear signal evolution. In the third stage with a full coating shell, the CD and CPL signals are inversely proportional to the CdS shell thickness. The island-like shell gives birth to the CPL signal, while the formation of full coating shell decreases the induced chirality. Such chiral and emissive NPLs provide an ideal platform for the rational design of semiconductor nanocrystals with chiroptical properties in areas of biomedicine, polarizers, and new generation of display devices.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 6
·期 9
·1194-1208
·
IF 8.683
Junjie Hao,Junzi Li,Meijuan Chen,Xijian Duan,Bing Xu,Yiwen Li,Tingchao He,Xiao Wei Sun,Marie-Hélène Delville,Jiaji Cheng
Induced chirality in colloidal semiconductor nanoparticles has received much attention in the past few years as an extremely sensitive spectroscopic tool and because of the promising applications of chiral quantum dots (QDs) in sensing, quantum optics, and spintronics. Yet, the origin of chiroptical effects induced in these nanoparticles is not fully understood, partly because almost all theoretical and experimental studies performed so far are based on the comparison of the g-factor of bulk solutions, which may not truly reflect the variation of the chiral signal in a single nanoparticle. This is because, at a given absorbance value, any change in the molar absorption coefficient at the single nanoparticle level does seriously affect the estimation of the real number of nanoparticles and comparison in-between solutions. Here, we show that using a top-down chemical etching process of colloidal two-component CdSe/CdS dot-in-rods (DRs) nanoparticles can facilitate precise control of nanocrystal solutions with identical concentrations, which cannot be achieved by bottom-up hot injection technology alone. This approach is highly required for studying ligand-induced chiral conduction mechanisms because it effectively eliminates the influence of both the concentrations of nanoparticles and ligands at the same time, instead of relying only on the g-factor related to absorbance. The results showed, thanks to the top-down selective domain etching system, that the shell layer had a negative correlation with the chirality of the first exciton peak (CdSe core contribution), but a positive correlation with the chirality of the CdS shell absorption. At the same time, the core integrity is crucial for DRs to maintain high circular dichroism (CD) and circularly polarized luminescence (CPL) signals. This work, on the one hand, advances the understanding of the fundamental origin of chiral conduction effects induced in semiconductor nanoparticles, and, on the other hand, opens a path to applications using chiral materials.
研究领域:
材料科学
·
化学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2022
·
IF 6.888
Xudong Li,Peixian Chen,Yong Xia,Ji Weng,Meijuan Chen,Tingchao He,Yiwen Li,Jiaji Cheng,Lei Zhang
Chiral tellurium nanoparticles have recently garnered tremendous attention as emerging inorganic nanomaterials with intrinsically chiral space groups owing to their potential in next-generation stereosynthesis, spintronics, and optoelectronics. Inspired by the chiral ligand-mediated synthetic strategy, we herein present hydrothermal-assisted synthesis of chiral polyhedral tellurium nanoparticles that provides differed chirogenesis than that of particles fabricated by wet chemistry in recent studies; the thiolated cysteine molecules change the morphology of tellurium nanoparticles from fundamental two-dimensional shapes to chiral three-dimensional polyhedra owing to the screw dislocation effects observed only during nanoparticle growth. However, the nanoparticles do not exhibit chiral behaviors at the nucleation stage. Further investigation indicates that the growth of chiral polyhedral tellurium nanoparticles is overwhelmingly affected by parameters such as the hydrothermal reaction time, amount of polyvinylpyrrolidone, and species of chiral molecules. We believe that these findings can provide new insights into the fundamental relationships among structural chirality, chiral ligands, screw dislocations, and chiral space groups in principle.
研究领域:
纳米材料
·
无机化学
·
材料科学
·
物理化学
·
手性
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Mingrui Liu,Guangmin Li,Shunsheng Wei,Hongfei Liu,Gaoling Yang
Chiral semiconductor nanocrystals (NCs) represent a promising class of materials for various applications, including biological sensing, photonics, and spin-polarized devices. However, the comprehension of the mechanisms underlying ligand-induced chiroptical effects in NCs has been limited by the constraints of current theoretical and experimental models, particularly those involving simple spherical NCs. In this study, we examined the relationship between optical activity and band structures in core–shell dot-in-rod NCs, specifically CdSe@CdS, ZnSe/CdS@CdS, and ZnSeTe/CdS@CdS dot-in-rod NCs, which were functionalized with chiral ligands. By manipulating the wave function distribution of electrons and holes within the dot-in-rod NCs, we demonstrated through circular dichroism (CD) measurements that a reduction in the number of holes within the synthesized dot-in-rod NCs correlates with a decrease in the g factor. This conclusion was corroborated by theoretical calculations. Furthermore, the fabrication of chiral CdS-Au heterojunctions and the application of electron quenchers revealed that the reduction of the g factor also suggests the significant role of electrons in the generation of chirality. Our findings not only enhance the understanding of the fundamental origins of induced chirality effects in semiconductor NCs but also provide a clear methodology for the design of optimal optically active chiral NCs, thereby paving the way for future applications utilizing chiroptical materials.
研究领域:
纳米材料
·
半导体物理
·
手性光学材料
·
量子点
·
光电子学
·
表面化学
·
理论凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）