Large-Area, Cost-Effective Nanoplasmonic Structures and Their Applications

Nanoscale functional material design and fabrication are essentially fundamental requirement for basic scientific researches and industrial applications of nano-science and engineering. Innovative, effective, reproducible, large-area uniform, tunable and robust nanostructure/material synthesis are still challenging. On the other hand, nanoscale controls of optical effects are a key element in advanced innovative nanophotonics and biophotonics, especially for biological and environmental molecular detection/imaging. Such optical modulation is also the critical technology in many optical devices such as a solar cell and a light-emitting diode (LED). However, optically tunable nanostructures/nanodevices have shown the big problem in the structural stability, thus resulting in a limited life-time under external loads, and moreover, if robust and tunable optical devices can be completed, the effort involved to precisely control the optical effects with structural strength and the reproducibility is so great that commercial-scale manufacture would never be cost-effective. Here, I would like to introduce the novel nanofabrications which rely on template-based nanolithography and present the surface plasmon (SP) which can effectively control the optical effects in nanostructures by simply modulating geometrical properties such as shape, size, and periodicity. Furthermore, in order to provide label-free and non-destructive molecular detection method, Raman scattering will be combined.

Plasmonic nanostructures with a localized surface plasmon resonance (LSPR), which is generated by the coupling of light to the collective oscillation of electrons on the nano-sized metallic surface, have generated considerable interest with the development of nanotechnology due to its ability to enhance the weak physical process such as the absorption of light. By adopting such a plasmonic nanostructure inside/onto/beneath a photoactive layer, a power conversion efficiency of solar cells could be improved because an electromagnetic (EM) field is greatly enhanced by plasmonic “hot spots”. Furthermore, optical biosensors such as surface-enhanced Raman scattering (SERS) could be designed with an ultrahigh sensitivity through a local field enhancement from the “hot spots”. A variety of optoelectronic devices and optical biosensors integrated with plasmonic nanostructures thus have been explosively studied and developed. In this study, we report large-area 3D plasmonic nanostructures though a high-throughput and cost-effective process. The surface morphology and optical properties are characterized by SEM and UV-vis. spectroscopy. Furthermore, their enhancement factor is evaluated by using SERS signals.