Self‐Assembly of Chiral Nematic Liquid Crystalline Phases of AgNR@SiO₂@Cysteine@CsPbBr₃ Hybrid Nanorods with Plasmon‐Dependent Photoluminescence

Abstract

The direct synthesis of a chiral nematic liquid crystalline phase of AgNR@SiO2@cysteine@CsPbBr3 hybrid nanorods (HNRs) is reported. The circular dichroism spectra can be divided into three components: (1) the interband absorption–enhanced optical activity of structural arrangement of cysteine (cys) molecules, 200–320 nm, (2) the chiral nematic liquid crystalline arrangement of the Ag nanorods (AgNRs), 350–450 nm, and (3) the exciton adsorption edge of the perovskite, 500–550 nm. The polarizing optical microscope images indicate that the chiroptical response of perovskite arises from chiral nematic crystalline arrangement rather than cys‐induced electronic coupling between a chiral ligand and otherwise achiral perovskite quantum dots (QDs). The luminescent intensity of CsPbBr3 QDs in AgNR@SiO2@cys@CsPbBr3 HNRs is boosted 87‐fold due to the local surface plasmon resonance field enhancement effect. Furthermore, the high‐performance green light emitting diode is constructed employing AgNR@SiO2@cys@CsPbBr3 complexes, which exhibit excellent luminescent properties. This work contributes insights into structure–property relationships and this strategy promisingly provides guidance for the other inorganic chiral semiconductor suprastructures.

Supramolecular Chirality Synchronization in Thin Films of Plasmonic Nanocomposites

“…This approach has been realized by tuning the interactions between NPs and chiral DNA, , peptides, , proteins, polymers, , silica, and small molecules used as templates, typically in colloidal or gel systems, and often mimicking the helical geometry of natural materials. − However, integration of these materials into functional devices requires accessible and scalable fabrication methods that rely on inexpensive and readily available constituents. One route to achieve this goal comprises the incorporation of metal nanoparticles within chiral liquid crystal (LC) matrices. − While yielding materials that exhibit interesting optical properties, this method is limited by the requisite that the organic template must be intrinsically chiral. We propose that achiral constituents can also be used to prepare chiral nanocomposites, which may reduce development costs, if only by broadening the scope of available organic building blocks.…”

Circular Polarized Light Emission in Chiral Inorganic Nanomaterials

“…The authors also prepared these nanorods with and without a layer of l-or d-cysteine deposited between SiO 2 and CsPbBr 3 (Figure 8d,e). [98] Considering the same sign of the 420 nm peak in CD spectra for l-and d-Cys, one can firmly conclude that the chiroptical activity at this wavelength originates from the meso-and microscale organization of the LC phase of the bent nanorods rather than the chirality of the cysteine coating. The CD peaks in 200-300 nm range display opposite signs for l-or d-cysteine indicating the optical activity of the chiral carbon centers in the surface ligands that fail to transfer the chirality to the perovskite or the LC phase of the nanorods (Figure 8f ).…”

“…d-f) Reproduced with permission. [98] Copyright 2020, Wiley-VCH. Image notations are verbatim reproduction from the original publications.…”

“…We note that the potential translation of these nanomaterials to LED devices is possible, even though the authors did not report CPLE. [98]…”

Chiral Ligand-Induced Structural Transformation of Low-Dimensional Hybrid Perovskite for Circularly Polarized Photodetection

“…In recent years, the introduction of structural asymmetry by using chiral organic groups has attracted a lot of attention. For instance, due to the non-centrosymmetric structures, chiral OIHPs are promising ferroelectric materials. − In addition, the coupling of structural asymmetry to spin–orbit coupling in chiral OIHPs may create Rashba-type spin polarization. ,, Owing to helicity-dependent excitons, OIHPs encompass the potential to be applied in a circularly polarized LED (CP-LED). ,− CPL detection is a key to some critical applications, such as drug screening, security surveillance, and quantum optics . Conventional CPL detectors require complex integration of components.…”