Yu Lim Chen

Fast fabrication of a Ag nanostructure substrate using the femtosecond laser for broad-band and tunable plasmonic enhancement.

Using a femtosecond laser, we have transformed the laser-direct-writing technique into a highly efficient method that can process AgO(x) thin films into Ag nanostructures at a fast scanning rate of 2000 μm(2)/min. The processed AgO(x) thin films exhibit broad-band enhancement of optical absorption and effectively function as active SERS substrates. Probing of the plasmonic hotspots with dyed polymer beads indicates that these hotspots are uniformly distributed over the treated area.

ZnO nanorod optical disk photocatalytic reactor for photodegradation of methyl orange

A low-cost and efficient photocatalytic reactor for environmental treatment and green technology was presented. ZnO nanorods firmly growing on polycarbonate optical disk substrate are generally perpendicular to the substrate as the immobilized photocatalyst of the spinning disk reactor. The photocatalytic efficiency and durability of the ZnO nanorods are effectively demonstrated.

Color rendering based on a plasmon fullerene cavity

Fullerene in the plasmon fullerene cavity is utilized to propagate plasmon energy in order to break the confinement of the plasmonic coupling effect, which relies on the influential near-field optical region. It acts as a plasmonic inductor for coupling gold nano-islands to the gold film; the separation distances of the upper and lower layers are longer than conventional plasmonic cavities. This coupling effect causes the discrete and continuum states to cooperate together in a cavity and produces asymmetric curve lines in the spectra, producing a hybridized resonance. The effect brings about a bright and saturated displaying film with abundant visible colors. In addition, the reflection spectrum is nearly omnidirectional, shifting by only 5% even when the incident angle changes beyond ± 60°. These advantages allow plasmon fullerene cavities to be applied to reflectors, color filters, visible chromatic sensors, and large-area display.

Plasmonic enhanced optical disk reactor for wastewater treatment

A process of growing large-area plasmonic-nano-particles-decorated ZnO nanorods on the polycarbonate optical disk substrate was developed, while a corresponding photocatalytic rotational reactor was fabricated. Hydrothermal process was adapted to grow ZnO nanorods perpendicular to the optical disk substrate at relatively lower temperature. The optical disk substrate has advantages of durable property in fast rotation and high impact-resistance. The plasmonic nano-particles, in this case, silver nano-particles, were deposed on the ZnO nanorods by direct sputtering. The morphology of ZnO nanorods and plasmonic nano-particles was investigated by Scanning Electron Microscope (SEM). The photocatalytic activity of the sample was evaluated by the degradation of methyl orange (MO) as a model compound in aqueous solution, and the decomposition rate of MO molecules is monitored by the optical spectroscopy measurements. In the optimized condition, less than 10% of the MO remained in the aqueous solution after a 20-minute treatment in the rotational reactor with our sample.

Zinc Oxide Nanorod Optical Disk Photocatalytic Reactor for Photodegradation

A spinning disk photocatalytic reactor for environmental treatment and green technology is demonstrated by using zinc oxide nanorods coated optical disk substrate. The efficiency of this novel photocatalytic reactor is confirmed experimentally.

Applications of plasmonic hotspots on laser-treated AgO x thin film

The femto-second-laser-treated AgOx thin film is used as the plasmon-active substrate for the applications of surface-enhanced Raman scattering (SERS), molecule sensing, and photocatalyst. The proposed technique is helpful for the solar energy harvest, green energy source, and biosensing with high efficiency and throughput.