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Plasmonic nanoparticles with chiral resonances in the visible wavelengths complement optical dissymmetry in the ultraviolet and near-infrared wavelengths in natural products and metamaterials respectively. Here, we show that under oxidative conditions, hot holes photogenerated with circularly polarized light in gold nanoprisms can spatially direct the photodeposition of lead oxide (PbO2), resulting in chiral nanostructures tunable with the polarization and wavelength of light. We observe a g-factor of 3.6 × 10–3, which can be attributed to the enhanced optical dissymmetry with PbO2 deposition of the side of nanoprisms upon illumination with green 532 nm light. Our finite-difference time-domain calculations support the site-specific photodeposition of PbO2 onto nanoprisms. This work shows that plasmonic nanoparticles can have tunable chiral properties imbued as a function of the wavelength and polarization of light. 

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. 

Lead-halide perovskite nanocrystals (NCs) are receiving much attention as a potential high-quality source of photons due to their superior luminescence properties in comparison to other semiconductor NCs. To date, research has focused mostly on NCs with little or no quantum confinement. Here, we measured the size- and temperature-dependent photoluminescence (PL) from strongly confined CsPbBr 3 quantum dots (QDs) with highly uniform size distributions, and examined the factors determining the evolution of the energy and linewidth of the PL with varying temperature and QD size. Compared to the extensively studied II–VI QDs, the spectral position of PL from CsPbBr 3 QDs shows an opposite dependence on temperature, with weaker dependence overall. On the other hand, the PL linewidth is much more sensitive to the temperature and size of the QDs compared to II–VI QDs, indicating much stronger coupling of excitons to the vibrational degrees of freedom both in the lattice and at the surface of the QDs. 

The utility of colloidal semiconductor quantum dots as a source of photons and charge carriers for photonic and photovoltaic applications has created a large field of research focused on tailoring and broadening their functionality beyond what an exciton can provide. One approach towards expanding the range of characteristics of photons and charge carriers from quantum dots is through doping impurity ions ( e.g. Mn 2+ , Cu + , and Yb 3+ ) in the host quantum dots. In addition to the progress in synthesis enabling fine control of the structure of the doped quantum dots, a mechanistic understanding of the underlying processes correlated with the structure has been crucial in revealing the full potential of the doped quantum dots as the source of photons and charge carriers. In this review, we discuss the recent progress made in gaining microscopic understanding of the photophysical pathways that give rise to unique dopant-related luminescence and the generation of energetic hot electrons via exciton-to-hot electron upconversion.