Phil N. Bartlett

Engineering SERS via absorption control in novel hybrid Ni/Au nanovoids

Nanoscale voids (or anti-nanoparticles) embedded in gold films possess plasmon modes with a strong field component at the cavity entrance, radically different to nanoparticle plasmon modes. By creating Ni/Au hybrid rim nanostructures we show how selective coupling to void plasmons provides strong electric field enhancements leading to large surface-enhanced Raman scattering (SERS) signals from molecules adsorbed on the nanovoid film. Since the rim plasmon modes are relatively independent of the supporting void material these results pave the way for hybrid nanovoid structures which combine plasmonic and catalytic properties of the constituent materials in a controllable and reproducible way.

Nanovoid plasmonic-enhanced low-cost photovoltaics

Gold and silver nanovoid structures generate localised plasmon modes which are harnessed to enhance organic and amorphous silicon solar cell performance. Higher absorption at plasmonic resonant wavelengths indicates significant potential for enhanced photocurrent and efficiency.

Fabrication of Nano-Structured Gold Arrays by Guided Self-assembly for Plasmonics

Gold inverse spherical nanoscale voids have been fabricated in linear arrays for directional plasmon measurements in the visible spectral range. We show that by KOH anisotropic etching in Si, we are able to make V-grooves in which latex spheres of the order of 500 nm self-assemble with largely defect-free cubic symmetry. Both single layer and multilayer assembly in a face-centered close-packed (FCC) lattice can be achieved by varying the width of the trenches. This template is subsequently used for electrodeposition of gold to create the inverse spherical nanovoids.

Strong coupling between plasmons and excitons in organic molecular J-aggregates on plasmonic crystals

By mapping optical absorption spectra from nanostructured plasmonic crystals coated with organic molecular J-aggregate films of cyanine dyes, strong coupling between J-aggregate excitons and two types of localized and delocalized plasmons is observed.

Enhanced optical fields and mixing of trapped plasmons in reproducibly engineered spherical nano-cavities

Metal nano-scale spherical voids embedded in thin films exhibit strong plasmon resonances that are tuneable using structural parameters of our 3D assembly process. Localised void plasmons possessing large field enhancements strongly couple to incident light.

Engineering localised plasmons on nanostructured metallic surfaces for surface-enhanced Raman spectroscopy

Reproducible SERS-active substrates with Raman enhancements >10,000 are designed by nano-templating gold and silver surfaces. Optimisation of the surface and localised plasmons matched to the exciting laser provide highly specific control, opening new applications spaces.

Templated metal nano-resonators for tunable optical microcavities

Our conveniently-fabricated spherical-reflector optical cavities with dimensions below 10 microns give localised tunable regions of greatly-enhanced light intensity suitable for applications in atom optics, microlasers, surface-enhanced single molecule detection, and many other research areas