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High Resolution Characterization of Plasmonic Hybridization in Silver Nanostructures
摘要： Surface plasmon resonances (SPR) in metallic nanostructures arise from the collective oscillation of conduction electrons, which create strong confined electric fields around the nanostructures. This confinement of electromagnetic (EM) energy at nanoscale dimensions holds potential towards the miniaturization of photonic devices [1]. Tremendous effort has been devoted towards optimization and design of nanostructures for several applications [2,3,4]. Most of these applications involve arrays of closely-spaced nanostructures: the plasmonic properties of the array differ from those of its isolated parts due to the interaction of evanescent fields. The study of SPR in these arrays, in particular the coupling of resonant modes, requires a characterization technique with both high spatial and energy resolution. Electron energy loss spectroscopy (EELS) meets these requirements, but has previously been limited to energies in the range of visible light or higher, mainly because of the relative intensities of the zero loss peak (ZLP) and low energy loss signal.
关键词： electron energy loss spectroscopy,metallic nanostructures,Surface plasmon resonances,hybridization,silver nanostructures
更新于2025-09-19 17:13:59
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0D/2D plasmonic Cu2-xS/g-C3N4 nanosheets harnessing UV-vis-NIR broad spectrum for photocatalytic degradation of antibiotic pollutant
摘要： Localized surface plasmon resonances (LSPRs) are usually achieved by some small grains of noble metal (Au, Ag et al.) to enhances the light absorption and charge carrier’s concentration of photocatalysts, but the wide application of noble metals is limited by their high cost. Here, we report the preparation of 0D/2D plasmonic Cu2-xS/g-C3N4 nanosheets (CSCNNs) and the utilization of LSPRs generated from Cu2-xS nanodots instead of noble metals to improve the photocatalytic activity for degradation of typical antibiotic levofloxacin (LVX). One-step hydrothermal method was employed to grow the highly effective in increasing the light absorption in near infrared (NIR) region and the theoretical analysis of band structure reveals the efficient separation and transmission mechanism of verify the strong light absorption capacity and longer carriers’ lifetime for CSCNNs. The dispersed Cu2-xS nanodots on the g-C3N4 nanosheets. Various characterization techniques region. Consequently, efficient photocatalytic degradation of LVX under full solar photogenerated electrons and holes. More importantly, LSPRs has been proved to be finite difference time domain (FDTD) simulations demonstrated that Cu2-xS LSPR-induced electromagnetic field in g-C3N4 nanosheets was far stronger than that of Ag and Au in NIR efficient LSPR photocatalysis system for treatment of antibiotic wastewater or other spectrum (UV-vis-NIR) can be achieved for CSCNNs. This work will lead to a cheap and photocatalytic applications.
关键词： levofloxacin degradation,Localized surface plasmon resonances,Cu2-xS,g-C3N4
更新于2025-09-19 17:13:59
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Plasmonics of Diffused Silver Nanoparticles in Silver/Nitride Optical Thin Films
摘要： Metal-dielectric multilayers are versatile optical devices that can be designed to combine the visible transmittance of dielectrics with the electronic properties of metals for plasmonic and meta-material applications. However, their performances are limited by an interfacial optical absorption often attributed entirely to the metal surface roughness. Here, we show that during deposition of AlN/Ag/AlN and SiNx/Ag/SiNx multilayers, significant diffusion of Ag into the top dielectric layer form Ag nanoparticles which excite localized surface plasmon resonances that are primarily responsible for the interfacial optical absorption. Based on experimental depth profiles, we model the multilayer’s silver concentration profile as two complementary error functions: one for the diffused Ag nanoparticles and one for the interface roughness. We apply the Maxwell-Garnett and Bruggeman effective medium theories to determine that diffusion characteristics dominate the experimental absorption spectra. The newfound metal nanoparticle diffusion phenomenon effectively creates a hybrid structure characteristic of both metal-dielectric multilayer and metal-dielectric composite.
关键词： Plasmonics,Metal-dielectric multilayers,Optical thin films,Silver nanoparticles,Localized surface plasmon resonances
更新于2025-09-16 10:30:52
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Ion irradiation of III–V semiconductor surfaces: From self-assembled nanostructures to plasmonic crystals
摘要： Ion-irradiation of semiconductor surfaces has emerged as a promising approach to generate a variety of self-organized nanostructures. Furthermore, the combination of focused-ion-irradiation with molecular-beam epitaxy provides unprecedented design and control of surfaces and interfaces of hybrid materials at the atomic level during fabrication. In this review, we describe the directed self-assembly of nanostructure arrays ranging from islands to nanorods to 3-dimensional nanoparticle (NP) arrays. First, we discuss focused-ion-irradiation of III–V surfaces, which leads to preferential sputtering of group V species, followed by the formation of group III-rich metallic nanostructures. For continued irradiation beyond a threshold dose, the nanoparticle (NP) evolution is determined by the sputtering yield and the local ion beam angle of incidence, resulting in arrays of nanoparticles, nanorods, or nanoparticle chains. In addition to describing the formation of close-packed embedded Ga:GaAs nanocomposites using overgrowth of focused-ion-beam fabricated NP arrays, we discuss the surface plasmon resonances of NP arrays as well as the influence of both surface and buried NP arrays on the GaAs photoluminescence efficiency. Finally, we discuss the potential of “plasmonic crystals” for plasmon-enhanced optoelectronics.
关键词： self-assembled nanostructures,ion irradiation,plasmonic crystals,molecular-beam epitaxy,III-V semiconductor,nanoparticle arrays,surface plasmon resonances,photoluminescence efficiency,focused-ion-beam
更新于2025-09-12 10:27:22
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Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability
摘要： Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags, phototherapeutic agents, and hot electron-based photocatalytic platforms. Despite having emerged as the cornerstone among plasmonic nanoparticles with respect to resonant strength and tunability, some well-known limitations have hampered their technological implementation. Herein we tackle these recognized intrinsic weaknesses, which stem from the complex, and thus computationally untreatable, morphology and the limited sample monodispersity, by proposing a novel 6-spike nanostar, which we have computationally studied and synthetically realized, as the epitome of 3D plasmonic nanoantenna with wide range plasmonic tunability. Our concerted computational and experimental effort shows that these nanostars combine the unique advantages of nanostructures fabricated from the top-down and those synthesized from the bottom-up, showcasing a unique plasmonic response that remains largely unaltered in going from the single particle to the ensemble. Furthermore, they display multiple, well-separated, narrow resonances, the most intense of which extends in space much farther than observed before for any plasmonic mode localized around a colloidal nanostructure. Importantly, the unique close correlation between morphology and plasmonic response leads the resonant modes of these particles to be tunable between 600 and 2000 nm, a unique feature that could find relevance in cutting edge technological applications.
关键词： 3D nano-antennas,colloidal nanostars,plasmon tunability,localized surface plasmon resonances,EELS
更新于2025-09-11 14:15:04
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Ultrahighly Enhanced Performance of Single Cadmium Selenide Nanobelt by Plasmonic Gold Particles
摘要： Noble metal nanoparticles have been demonstrated by a huge application prospect for photodetector (PD) due to their unique and tunable optical properties. Herein, a simple strategy is presented by a combination of gold nanoparticles (Au NPs) and broadband photoresponse cadmium selenide nanobelts (CdSe NBs) to get ultrasensitive, broadband photoresponse (300–720 nm) and tunable photoresponse PD. Concretely, the Au NPs are fabricated on CdSe NBs via ion sputtering and annealing, and the morphology of Au NPs is systematically adjusted by simply tuning the sputter time from 60 to 140 s. Compared with the pure CdSe NB PD, the Au NPs hybrid CdSe NB PD exhibits a high responsivity, especially in the range of 525–575 nm with low light intensity (enhancement of (cid:3)2). The response time of the hybrid PD is (cid:1)2894% at 550 nm with 79.6 μW cm decreased substantially from 0.8 to 0.2 ms. More importantly, the hybrid PD possesses a tunable absorption in the range of 538–580 nm, which is bene?ted from tunable plasmon resonance of Au NPs. These results are con?rmed by the theoretical simulation. It is believed that this strategy offers new opportunities to design ultrasensitive, broadband spectra, and tunable wavelength PD.
关键词： cadmium selenide nanobelts,photodetectors,the discrete dipole approximation,surface plasmon resonances
更新于2025-09-11 14:15:04
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pH-regulated reversible photoluminescence and localized surface plasmon resonances arising from molybdenum oxide quantum dot
摘要： Localized surface plasmon resonances (LSPR) and photoluminescence are important for applications of transition-metal oxides. However, simultaneous control of these optical properties is challenging. Here, a facile strategy is presented that simultaneously tunes photoluminescence and visible LSPR of molybdenum oxide quantum dots (MoOx QDs) by controlling lattice vacancies. Specifically, N-doped MoOx QDs were prepared with a one-pot protocol. The introduction of N in MoOx QDs surfaces via ammonia (NH3) not only trapped oxygen molecules in the process of forming MoOx QDs, but also provided enough free electrons to enable tunable optical properties. Thus, a MoOx QD-based dual-modal fluorescence and LSPR assay was demonstrated via lattice vacancy concentration tuning. Upon introduction of H+ or OH?, pH-reversible tunability of the fluorescence and plasmonic resonance was observed. The dual-mode probe was used to detect extreme acidity in bacterial cells. Overall, tunable LSPR and photoluminescence within one nanostructure via pH-regulation should enable multi-modal signal-outputs for sensing platforms and photoelectric nanodevices.
关键词： Localized surface plasmon resonances,Molybdenum oxide,pH sensor,Dual-modal sensor,Photoluminescence
更新于2025-09-11 14:15:04
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Optical Tunability of Silver-Dielectric-Silver Multi-Layered Cylindrical Nanotubes Using Quasi-Static Approximation
摘要： Local surface plasmon resonances (LSPRs) of silver-dielectric-silver multi-layered (SDS-ML) nanotubes are studied by theoretical calculations. Based on quasi-static approximation, the absorption cross section of SDS-ML nanotubes is plotted as a function of wavelength. The results show that SDS-ML nanotubes exhibit strong coupling between the cylindrical silver and nanotubes. The absorption spectra of LSPRs are strongly influenced by changing the radius of the inner core and outer nanotube shell. The longer wavelength is red-shifted by increasing the radius of the inner core and outer shell, while the short wavelength shows the opposite properties. These phenomena are explained by the plasmon hybridization theory. In addition, for clarity, the distributions of electric field intensity at their plasmon resonance wavelengths are also studied.
关键词： Local surface plasmon resonances,quasi-static approximation,silver-dielectric-silver multi-layered nanotubes,plasmon hybridization theory
更新于2025-09-09 09:28:46
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Ultrathin tungsten bronze nanowires with efficient photo-to-thermal conversion behavior
摘要： In this work, we describe a simple one-step solvothermal method to synthesize ultrathin quaternary tungsten bronze nanowires (QTBNWs). In addition, a series of alkali metal-doped QTBNWs can be prepared by simply changing the type of starting alkali carbonate and tungstate. The as-synthesized QTBNWs exhibits strong near-infrared (NIR) rays absorption, high visible light transmission and excellent photo-to-thermal conversion behavior, which are superior to those of tungsten bronze nanorods and ternary TBNWs. And its excellent photothermal performance should be attributed to great localized surface plasmon resonances (SPR).
关键词： solvothermal method,photo-to-thermal conversion,near-infrared absorption,ultrathin tungsten bronze nanowires,surface plasmon resonances
更新于2025-09-09 09:28:46
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Reversible Photodoping of TiO <sub/>2</sub> Nanoparticles for Photochromic Applications
摘要： Observations on the strong photochromic effect of crystalline TiO2 quantum dots (mean size ≈ 4 nm) are presented. The synthesized quantum dots consist of irregularly shaped anatase TiO2 nanoparticles (NPs) and are dispersed in butanol (8% by mass). Obtained NPs exhibit a dramatic photoresponse to UV light, enabling effective transmittance modulation in a broad wavelength range extending from the visible to near-infrared region, and even the thermal black body radiation regime beyond 10 μm. The exceptional photoresponse is attributed to hole-scavenging by butanol, TiO2 self-reduction, injection of electrons to the conduction band, and consequent localized surface plasmon resonances in NPs. The observed optical effect is reversible, and the initial high transmittance state can be restored simply by exposing the NPs to air. The applied NP synthesis route is economic and can be easily scaled for applications such as smart window technologies.
关键词： UV light,TiO2 nanoparticles,localized surface plasmon resonances,transmittance modulation,photochromic
更新于2025-09-04 15:30:14