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XPS and thermal studies of silver doped SiO2 matrices for plasmonic applications
摘要： Silver nanocrystals doped SiO2 matrices were synthesized through sol–gel route using acid catalyst. The prepared silica matrices with different concentrations of silver were annealed at different temperatures and characterized using, XRD, FTIR, Absorption spectroscopy, XPS, thermogravimetric and differential thermal analysis. The XRD data con?rm the amorphous nature of silica and crystalline nature of silver nanocrystals. Using the Fourier-transform infrared red spectrum the formation of silica glass was con-?rmed. The characteristic Surface Plasmon Resonance of silver nanoparticles obtained around 400 nm from the absorption spectrum. The observed blue shift and skewness in SPR with increasing silver con-centrations were studied. The 3d doublet state of silver at a binding energy of 368.4 eV with the splitting of 6 eV obtained in XPS con?rm the state Ag0 along with the presence of a minor quantity of silver (II) oxide. The thermal stability and nature were analyzed using TGA-DTG and DTA and showed good thermal stability from 400 (cid:1)C to higher temperatures.
关键词： Sol-gel,Surface plasmon resonance,Thermal analysis,XPS,Silver nanocrystals
更新于2025-09-23 15:19:57
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Plasmonic Electronsa??Driven Solara??toa??Hydrocarbon Conversion over Au NR@ZnO Corea??Shell Nanostructures
摘要： This work demonstrates the long-range redox reactivity of gold plasmon-generated hot electrons for solar-driven CO2 conversion. A series of Au NR@ZnO core-shell photocatalysts with a tunable shell thickness are rationally designed to achieve the solar-to-CH4 conversion, where the hot plasmonic electrons-induced photoreduction takes place on the polar oxide moiety. The shell thickness-independent activity implies that the core, gold nanorods, plays a dominant role in the CH4 generation. The ZnO metal oxide semiconductor shell is beneficial to prolong the lifetime of hot electrons, thereby enhancing the photocatalytic efficiency. However, the thickness of ZnO shell is not relevant to the production rate. Both of these two parts are co-excitated by solar light and synergetic enhance the photocatalytic activity.
关键词： gold nanorod,core-shell nanostructure,ZnO,photocatalysis,CO2 photoreduction,plasmon resonance
更新于2025-09-23 15:19:57
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Cephalopod-inspired versatile design based on plasmonic VO2 nanoparticle for energy-efficient mechano-thermochromic windows
摘要： Privacy and energy-saving are key functionalities for next-generation smart windows, while to achieve them independently on a window is challenging. Inspired by the cephalopod skin, we have developed a versatile thermo- and mechano-chromic design to overcome such challenge and reveal the mechanism via both experiments and simulations. The design is facile with good scalability, consisted of well-dispersed vanadium dioxide (VO2) nanoparticles (NPs) with temperature-dependent localized surface plasmon resonance (LSPR) in transparent elastomers with dynamic micro wrinkles. While maintaining a fixed solar energy modulation of (?Tsol), the design can dynamically control visible transmittance (Tvib) from 60% to 17%, adding a new dimension to VO2-based smart windows. We prove that the optical modulation relies on the microtexture-induced broadband diffraction and the plasmon-enhanced near-infrared absorbance of VO2 NPs. We further present a series of modified designs towards additional functionalities. This work opens an avenue for independent dual-mode windows and it may inspire development from fundamental material, optic, and mechanical science to energy-related applications.
关键词： Mechanochromic,Localized Surface Plasmon Resonance,Solar Energy Modulation,Bio-inspired,Wrinkle,Smart Window
更新于2025-09-23 15:19:57
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Surface plasmon-enhanced solution-processed phosphorescent organic light-emitting diodes by incorporating gold nanoparticles
摘要： Organic light-emitting diodes (OLEDs) have attracted increasing attention due to their superiority as high quality displays and energy-saving lighting. However, improving the efficiency of solution-processed devices especially based on blue emitter remains a challenge. Excitation of surface plasmons on metallic nanoparticles has potential for increasing the absorption and emission from optoelectronic devices. We demonstrate here that the incorporation of gold nano particles (GNPs) in the hole injection layer of poly(3,4-ethylene dioxythiophene):polystyrene sulfonic acid with an appropriate size and doping concentration can greatly enhance the efficiency OLED device especially at higher voltage. Apparently, the spectral of the multiple plasmon resonances of the GNPs and the luminescence of the emitting materials significantly overlap with each other. At 1000?cd/m2 for example, the power efficiency of a studied green device is increased from 29.0 to 36.2 lm/W1, an increment of 24.8%, and the maximum brightness improved from 21,550 to 27,810?cd/m2, an increment of 29.1%, as 2 wt% of a 12 nm GNP is incorporated. Remarkably, designed blue OLED also exhibited an increment of 50% and 35% in power efficacy at 100 and 1,000 cd/m2, respectively, for same device structure. The reason why the enhancement is marked may be attributed to a strong absorption of the short-wavelength emission from the device by the gold nano particles, which in turn initiates a strong surface plasmon resonance effect, leading to a high device efficiency.
关键词： OLED,surface plasmon resonance effect,efficiency,gold nano particle,size effect
更新于2025-09-23 15:19:57
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Rapid label-free detection of intact pathogenic bacteria <i>in situ via</i> surface plasmon resonance imaging enabled by crossed surface relief gratings
摘要： The unique plasmonic energy exchange occurring within metallic crossed surface relief gratings (CSRGs) has recently motivated their use as biosensors. However, CSRG-based biosensing has been limited to spectroscopic techniques, failing to harness their potential for integration with ubiquitous portable electronics. Here, we introduce biosensing via surface plasmon resonance imaging (SPRi) enabled by CSRGs. The SPRi platform is fully integrated including optics and electronics, has bulk sensitivity of 613 Pixel Intensity Unit (PIU)/Refractive Index Unit (RIU), a resolution of 10?6 RIU and a signal-to-noise ratio of ～33 dB. Finite-Difference Time-Domain (FDTD) simulations confirm that CSRG-enabled SPRi is supported by an electric field intensity enhancement of ～30 times, due to plasmon resonance at the metal-dielectric interface. In the context of real-world biosensing applications, we demonstrate the rapid (<35 min) and label-free detection of uropathogenic E. coli (UPEC) in PBS and human urine samples for concentrations ranging from 103 to 109 CFU mL?1. The detection limit of the platform is ～100 CFU mL?1, three orders of magnitude lower than the clinical detection limit for diagnosis of urinary tract infection. This work presents a new avenue for CSRGs as SPRi-based biosensing platforms and their great potential for integration with portable electronics for applications requiring in situ detection.
关键词： crossed surface relief gratings,portable electronics,biosensing,pathogenic bacteria detection,surface plasmon resonance imaging
更新于2025-09-23 15:19:57
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Tailoring Carrier Dynamics in Perovskite Solar Cells via Precise Di-mension and Architecture Control and Interfacial Positioning of Plasmonic Nanoparticles
摘要： Placing plasmonic nanoparticles (NPs) in close proximity to semiconductor nanostructures renders effective tuning of the optoelectronic properties of semiconductors through the localized surface plasmon resonance (LSPR)-induced enhancement of light absorption and/or promotion of carrier transport. Herein, we report on, for the first time, the scrutiny of carrier dynamics of perovskite solar cells (PSCs) via sandwiching monodisperse plasmonic/dielectric core/shell NPs with systematically varied dielectric shell thickness yet fixed plasmonic core diameter within electron transport layer (ETL). Specifically, a set of Au NPs with precisely controlled dimensions (i.e., fixed Au core diameter and tunable SiO2 shell thickness) and architectures (plain Au NPs and plasmonic/dielectric Au/SiO2 core/shell NPs) are first crafted by capitalizing on the star-like block copolymer nanoreactor strategy. Subsequently, these monodisperse NPs are sandwiched between the two consecutive TiO2 ETLs. Intriguingly, there exists a critical dielectric SiO2 shell thickness, below which hot electrons from Au core are readily injected to TiO2 (i.e., hot electron transfer (HET)); this promotes local electron mobility in TiO2 ETL, leading to improved charge transport and increased short-circuit current density (Jsc). It is also notable that the HET effect moves up the Fermi level of TiO2, resulting in an enhanced built-in potential and open-circuit voltage (Voc). Taken together, the PSCs constructed by employing a sandwich-like TiO2/Au NPs/TiO2 ETL exhibit both greatly enhanced Jsc and Voc, delivering champion PCEs of 18.81% and 19.42% in planar and mesostructured PSCs, respectively. As such, the judicious positioning of rationally designed monodisperse plasmonic NPs in ETL affords effective tailoring of carrier dynamics, thereby providing a unique platform for developing high-performance PSCs.
关键词： hot electron transfer,perovskite solar cells,plasmonic nanoparticles,carrier dynamics,localized surface plasmon resonance
更新于2025-09-23 15:19:57
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Tents, Chairs, Tacos, Kites, and Rods: Shapes and Plasmonic Properties of Singly Twinned Magnesium Nanoparticles
摘要： Nanostructures of some metals can sustain light-driven electron oscillations called localized surface plasmon resonances, or LSPRs, that give rise to absorption, scattering, and local electric field enhancement. Their resonant frequency is dictated by the nanoparticle (NP) shape and size, fueling much research geared towards discovery and control of new structures. LSPR properties also depend on composition; traditional, rare and expensive noble metals (Ag, Au) are increasingly eclipsed by earth-abundant alternatives, with Mg being an exciting candidate capable of sustaining resonances across the ultraviolet, visible, and near-infrared spectral ranges. Here, we report numerical predictions and experimental verifications of a set of shapes based on Mg NPs displaying various twinning patterns including (10 1), (10 2), (10 3) and (11 1), that create tent, chair, taco and kite-shaped NPs, respectively. These are strikingly different from what is obtained for typical plasmonic metals because Mg crystallizes in a hexagonal close packed structure, as opposed to the cubic Al, Cu, Ag, and Au. A numerical survey of the optical response of the various structures, as well as the effect of size and aspect ratio, reveals their rich array of resonances, which are supported by single particle optical scattering experiments. Further, corresponding numerical and experimental studies of the near-field plasmon distribution via scanning transmission electron microscopy electron-energy loss spectroscopy unravels a mode nature and distribution that are unlike those of either hexagonal plates or cylindrical rods. These NPs, made from earth-abundant Mg, provide interesting ways to control light at the nanoscale across the ultraviolet, visible, and near-infrared spectral ranges.
关键词： nanoplasmonics,nanoparticle shape,magnesium nanoparticles,localized surface plasmon resonance,electron-energy loss spectroscopy,Wulff construction
更新于2025-09-23 15:19:57
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Effective medium theory to the description of plasmonic resonances: Role of Au and Ti nanoparticles embedded in MoO3 thin films
摘要： The growing interest in functional transition metal oxides for efficient energy consumption or in the bio-sensing process; indicates that is necessary to develop a new theoretical method that describes experiments. This article presents a new theoretical methodology to characterize molybdenum trioxide (MoO3) thin films doped with resonant gold – nanoparticles (Au – NPs) and non-resonant titanium – nanoparticles (Ti – NPs). The modulation of surface plasmon resonance (SPR) and the implications in the MoO3 transmittance spectrum is described by applying an effective medium theory. The transmittance modulation was modified by variating three parameters, the radius of the NPs, the concentration of the NPs as well as the variation of the MoO3 thin films thickness. It was found that the nanoparticles concentration is the most important parameter in the transmittance modulation. Additionally, the orthorhombic and monoclinic structure of MoO3 was studied, from which it was obtained that the monoclinic structure of the MoO3 doped with Au – NPs favors the reduction in the transmittance values in the visible region which is associated with the increase of the SPR signal. Similar analyses are performed for non-resonant nanoparticles such as Ti, where it was found that optical modulation is not as marked as the case of gold nanoparticles.
关键词： optical modulation,plasmonic resonances,Au and Ti nanoparticles,surface plasmon resonance,MoO3 thin films,effective medium theory
更新于2025-09-23 15:19:57
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Plasmonic Nanoparticles in Dielectrics Synthesized by Ion Beams: Optical Properties and Photonic Applications
摘要： The zero-dimensional metallic nanoparticles (NPs) have attracted tremendous attention in various areas owing to the collective oscillation of electron gas that couples with electromagnetic field, known as localized surface plasmon resonance (LSPR). In practical applications, the tailoring of LSPR effect is of significant importance for promising photonic devices with designed nanocomposite systems and enhanced optical properties. Ion beam technology has been demonstrated to be an efficient method to fabricate NPs embedded in dielectrics for LSPR tailoring and material modification. By manipulating the parameters of ion beams, the shape, size, and structure of NPs can be well controlled, which enables the dielectrics to possess novel linear and nonlinear optical properties. In this review, the latest research progress on the ion beam synthesis of various NPs is systematically summarized. The tailoring of linear and nonlinear optical properties of dielectrics by NPs is discussed in detail. Selected applications are presented to indicate the development of the plasmonic NPs in dielectric systems for photonic applications.
关键词： localized surface plasmon resonance,ion beam modification,nonlinear optical responses,photonic applications,plasmonic nanoparticles
更新于2025-09-23 15:19:57
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Size-Dependent Thermo- and Photoresponsive Plasmonic Properties of Liquid Crystalline Gold Nanoparticles
摘要： Achieving remotely controlled, reversibly reconfigurable assemblies of plasmonic nanoparticles is a prerequisite for the development of future photonic technologies. Here, we obtained a series of gold-nanoparticle-based materials which exhibit long-range order, and which are controlled with light or thermal stimuli. The influence of the metallic core size and organic shell composition on the switchability is considered, with emphasis on achieving light-responsive behavior at room temperature and high yield production of nanoparticles. The latter translates to a wide size distribution of metallic cores but does not prevent their assembly into various, switchable 3D and 2D long-range ordered structures. These results provide clear guidelines as to the impact of size, size distribution, and organic shell composition on self-assembly, thus enhancing the smart design process of multi-responsive nanomaterials in a condensed state, hardly attainable by other self-assembly methods which usually require solvents.
关键词： nanoparticles,photoresponsive materials,self-assembly,liquid crystals,surface plasmon resonance
更新于2025-09-23 15:19:57