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Abstract Chiral perovskite nanocrystals have emerged as an interesting chiral excitonic platform that combines both structural flexibility and superior optoelectronic properties. Despite several recent demonstrations of optical activity in various chiral perovskite nanocrystals, efficient circularly polarized luminescence (CPL) with tunable energies remains a challenge. The chirality imprinting mechanism as a function of perovskite nanocrystal dimensionality remains elusive. Here, atomically thin inorganic perovskite nanoplatelets (NPLs) are synthesized with precise control of layer thickness and are functionalized by chiral surface ligands, serving as a unique platform to probe the chirality transfer mechanism at the organic/perovskite interface. It is found that chirality is successfully imprinted into mono‐, bi‐, and tri‐layer inorganic perovskite NPLs, exhibiting tunable circular dichroism (CD) and CPL responses. However, chirality transfer decreases in thicker NPLs, resulting in decreased CD and CPL dissymmetry factors for thicker NPLs. Aided by large‐scale first‐principles calculations, it is proposed that chirality transfer is mainly mediated through a surface distortion rather than a hybridization of electronic states, giving rise to symmetry breaking in the perovskite lattice and spin‐split conduction bands. The findings described here provide an in‐depth understanding of chirality transfer and design principles for distorted‐surface perovskites for chiral photonic applications.
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This content will become publicly available on June 17, 2026
Increasing the Structural Chirality of Metal Nanocrystals Created by Circularly Polarized Light via Surface Ligand Engineering
Abstract Plasmon‐mediated synthesis enables isotropic metal nanocrystal growth with linearly polarized light. This limits the effect of the polarization of incident light during synthesis, and thus restricts the structural chirality of nanocrystals produced with circularly polarized light (CPL). This study here demonstrates that surface engineering of initial achiral silver nanorods (AgNRs) can enhance the structural chirality of the resulting nanostructures produced with CPL. Specifically, the surface ligand hexadecyltrimethylammonium bromide (CTAB) stabilizes the lateral (100) facet‐terminated sides of achiral AgNRs and inhibits lateral growth. This surface engineering with achiral ligands results in increased dissymmetry of the nanostructures during the early stages of photo‐growth and leads to the formation of “hook” structures, where silver preferentially deposits near the tips of the nanorods. Upon further CPL illumination, these “hook” structures exhibit a significantly larger dissymmetry in the local electric field enhancement distribution compared to the initial achiral AgNRs. This highly dissymmetric electric field enhancement profile influences subsequent growth, resulting in AgNRs with enhanced structural chirality. Notably, the optical dissymmetry of these chiral nanostructures withg‐factor≈0.05 is an order of magnitude greater than that reported in previous studies conducted under similar chemical conditions but without surface engineering.
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- Award ID(s):
- 2147792
- PAR ID:
- 10606675
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 21
- Issue:
- 32
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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