Search results for "surface plasmon resonance"
showing 10 items of 208 documents
Refractive micro-optical elements for surface plasmons: from classical to gradient index optics.
2010
Controlling the propagation of surface plasmons along a metal-dielectric interface is a key feature for the development of surface plasmon based circuits. We have designed various two-dimensional refractive dielectric optical elements for surface plasmons (SP) and characterized their capacity to route SP, using near- or far-field techniques. We first present basic devices analogous to usual optical components and the associated challenges for SP optics. We then use a metamaterial approach to locally vary the refractive index and fabricate gradient index structures for SP circuitry.
Evaluating plasmonic transport in current-carrying silver nanowires
2013
cited By 1; International audience; Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends …
Birth of the Localized Surface Plasmon Resonance in Monolayer-Protected Gold Nanoclusters
2013
Gold nanoclusters protected by a thiolate monolayer (MPC) are widely studied for their potential applications in site-specific bioconjugate labeling, sensing, drug delivery, and molecular electronics. Several MPCs with 1-2 nm metal cores are currently known to have a well-defined molecular structure, and they serve as an important link between molecularly dispersed gold and colloidal gold to understand the size-dependent electronic and optical properties. Here, we show by using an ab initio method together with atomistic models for experimentally observed thiolate-stabilized gold clusters how collective electronic excitations change when the gold core of the MPC grows from 1.5 to 2.0 nm. A …
Super Resolved Holographic Configurations
2014
No Label Required: Protein Binding at Membrane Interfaces Visualized through Colloid Phase Transitions
2004
Plasmon-enhanced photocurrent in quasi-solid-state dye-sensitized solar cells by the inclusion of gold/silica core–shell nanoparticles in a TiO2 phot…
2013
Direct evidence of the effects of the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) in TiO2 photoanodes on the performance enhancement in quasi-solid-state dye-sensitized solar cells (DSCs) is reported by comparing gold/silica core–shell nanoparticles (Au@SiO2 NPs) and hollow silica nanoparticles with the same shell size of the core–shell nanoparticles. The Au nanoparticles were shelled by a thin SiO2 layer to produce the core–shell structure, and the SiO2 hollow spheres were made by dissolving the Au cores of the gold/silica core–shell nanoparticles. Therefore, the size and morphology of the SiO2 hollow spheres were the same as the Au@SiO2 NPs. The energy conver…
Direct measurement of optical losses in plasmon-enhanced thin silicon films (Conference Presentation)
2018
Plasmon-enhanced absorption, often considered as a promising solution for efficient light trapping in thin film silicon solar cells, suffers from pronounced optical losses i.e. parasitic absorption, which do not contribute to the obtainable photocurrent. Direct measurements of such losses are therefore essential to optimize the design of plasmonic nanostructures and supporting layers. Importantly, contributions of useful and parasitic absorption cannot be measured separately with commonly used optical spectrophotometry. In this study we apply a novel strategy consisting in a combination of photocurrent and photothermal spectroscopic techniques to experimentally quantify the trade-off betwee…
Controlling the oxidation processes of Zn nanoparticles produced by pulsed laser ablation in aqueous solution
2016
We used online UV-VIS optical absorption and photoluminescence spectra, acquired during and after pulsed laser ablation of a Zinc plate in aqueous solution, to investigate the effect of the laser repetition rate and liquid environment on the oxidation processes of the produced nanoparticles. A transient Zn/ZnO core-shell structure was revealed by the coexistence of an absorption peak around 5.0 eV due to Zn surface plasmon resonance and of an edge at 3.4 eV coming from wurtzite ZnO. The growth kinetics of ZnO at the various repetition rates, selectively probed by the excitonic emission at 3.3 eV, began immediately at the onset of laser ablation and was largely independent of the repetition …
Oxidation of Zn nanoparticles probed by online optical spectroscopy during nanosecond pulsed laser ablation of a Zn plate in H2O
2015
We report online UV-Visible absorption and photoluminescence measurements carried out during and after pulsed laser ablation of a zinc plate in water, which clarify the events leading to the generation of ZnO nanoparticles. A transient Zn/ZnO core-shell structure is revealed by the coexistence of the resonance absorption peak around 5.0 eV due to Zn surface plasmon resonance and the edge at 3.5 eV of ZnO. The growth kinetics of ZnO, selectively probed by the exciton luminescence at 3.3 eV, begins only after a ∼30 s delay from the onset of laser ablation. We also detect the luminescence at 2.3 eV of ZnO oxygen vacancies, yet rising with an even longer delay (∼100 s). These results show that …
Plasmonic photoluminescence enhancement by silver nanowires
2015
Strong enhancement of photoluminescence is demonstrated for CdS nanocrystals and ruthenium-based dye (N719) due to localized surface plasmon resonance of silver nanowires placed on silver film. Alternative reasons for photoluminescence modulation such as mirror effect and uneven coating by dye or nanocrystals due to geometrical factors are discussed. An artifact such as carbon contamination at the surface of silver nanowires at high laser power is demonstrated and taken into consideration. Silver nanowire on silver film is proved to be an effective system for photoluminescence enhancement by localized surface plasmon resonance.