Tunable Three-Dimensional Plasmonic Arrays for Large Near-Infrared Fluorescence Enhancement.

Metal-enhanced fluorescence (MEF), resulting from the near-field interaction of fluorophores with metallic nanostructures, has emerged as a powerful tool for dramatically improving the performance of fluorescence-based biomedical applications. Allowing for lower autofluorescence and minimal photoinduced damage, the development of multifunctional and multiplexed MEF platforms in the near-infrared (NIR) windows is particularly desirable. Here, a low-cost fabrication method based on nanosphere lithography is applied to produce tunable three-dimensional (3D) gold (Au) nanohole-disc arrays (Au-NHDAs).

Plasmonic enhanced CuO-Au-BFO photocathodes for solar hydrogen production.

A novel CuO-Au-BFO heterostructure photocathode was constructed which significantly improved the efficiency of photo-generated carrier transfer for solar hydrogen production. A BiFeO (BFO) ferroelectric film was synthesized on top of a CuO layer by a sputtering process. The BFO layer acted to protect the CuO layer from photochemical corrosion, increasing photoelectrochemical (PEC) stability.

Tuneable fluorescence enhancement of nanostructured ZnO arrays with controlled morphology.

Zinc oxide (ZnO) nanorods (NRs) have been demonstrated as a promising platform for enhanced fluorescence-based sensing. It is, however, desirable to achieve a tuneable fluorescence enhancement with these platforms so that the fluorescence output can be adjusted based on the real need. Here we show that the fluorescence enhancement can be tuned by changing the diameter of the ZnO nanorods, simply controlled by potassium chloride (KCl) concentration during synthesis, using arrays of previously developed aligned NRs (a.

Enhancement of the upconversion photoluminescence of hexagonal phase NaYF:Yb,Er nanoparticles by mesoporous gold films.

Efficient enhancement of photoluminescence in rare-earth activated upconversion materials is of great significance for their practical applications in various fields. In this work, three-dimensional mesoporous gold films were fabricated by a low-cost and facile dealloying approach to improve the upconversion photoluminescence efficiency. The mesoporous Au films exhibit good chemical stability, large-area uniformity and abundant distribution of porous nanospaces.

Significant Broadband Photocurrent Enhancement by Au-CZTS Core-Shell Nanostructured Photocathodes.

Copper zinc tin sulfide (CZTS) is a promising material for harvesting solar energy due to its abundance and non-toxicity. However, its poor performance hinders their wide application. In this paper gold (Au) nanoparticles are successfully incorporated into CZTS to form Au@CZTS core-shell nanostructures.

Predicting the fluorescent enhancement rate by gold and silver nanospheres using finite-difference time-domain analysis.

Metal-induced fluorescence enhancement (MIFE) is a promising strategy for increasing the sensitivity of fluorophores used in biological sensors. This study uses the finite-difference time-domain technique to predict the fluorescent enhancement rate of a fluorophore molecule in close proximity to a gold or silver spherical nanoparticle. By considering commercially available fluorescent dyes the computed results are compared with the published experimental data.

Diffuse scattering from hemispherical nanoparticles at the air-silicon interface.

There has been much recent interest in the application of plasmonics to improve the efficiency of silicon solar cells. In this paper we use finite difference time domain calculations to investigate the placement of hemispherical gold nanoparticles on the rear surface of a silicon solar cell. The results indicate that nanoparticles protruding into the silicon, rather than into air, have a larger scattering efficiency and diffuse scattering into the semiconductor.

Plasmonic fluorescence enhancement by metal nanostructures: shaping the future of bionanotechnology.

This review focuses on metal enhanced fluorescence (MEF) and its current and future applications in biotechnology. The mechanisms of MEF are discussed in terms of the additional radiative and nonradiative decay rates caused by the close proximity of the metal. We then review the current MEF materials and structures that show promise in bioapplications.

Tunable synthesis of ordered zinc oxide nanoflower-like arrays.

A novel approach to fabricate an ordered array of ZnO nanoflowers, consisting of uniform polymer cores of 100s of nanometer diameter decorated with ZnO nanorods of 10s of nanometer diameter, is presented. The 2-stage method combines the formation of ZnO seed layer by pulsed laser deposition (PLD) onto a colloidally assembled polystyrene sphere monolayer and the subsequent hydrothermal growth of ZnO nanowires (NWs). The main advantages of this methodology are low cost and the large area scalability of perfectly ordered hierarchical structures.

Au nanostructures by colloidal lithography: from quenching to extensive fluorescence enhancement.

Enhanced local electric fields are created by nanoparticles when pumped at wavelengths corresponding to Localised Surface Plasmon Resonance (LSPR) modes, leading to Metal Induced Fluorescence Enhancement (MIFE). This paper describes the fluorescent enhancement due to reproducible and tuneable Au nanostructures on glass substrates fabricated over large areas by colloidal lithography. Interparticle separation, particle resonance, and the fluorescent dye properties (quantum yield and emission/excitation wavelengths) are all important factors influencing the fluorescent enhancement.

Optical characteristics of silicon nanowires grown from tin catalyst layers on silicon coated glass.

The optical characteristics of silicon nanowires grown on Si layers on glass have been modeled using the FDTD (Finite Difference Time Domain) technique and compared with experimental results. The wires were grown by the VLS (vapour-liquid-solid) method using Sn catalyst layers and exhibit a conical shape. The resulting measured and modeled absorption, reflectance and transmittance spectra have been investigated as a function of the thickness of the underlying Si layer and the initial catalyst layer, the latter having a strong influence on wire density.

Scattering of light into silicon by spherical and hemispherical silver nanoparticles.

The interaction of light with noble metal nanoparticles deposited onto the top surface of a semiconductor has been investigated using the finite-difference time-domain method. The scattering is calculated for spherical and hemispherical silver nanoparticles placed in a periodic two-dimensional array on the upper surface of a semi-infinite silicon substrate. The results show that the contact area between hemispherical particles and the silicon significantly reduces the forward scattering.