| Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 105 === The EBL-defined periodic ZnO-elevated gold dimer nanostructures for surface-enhanced Raman spectroscopy with strong electromagnetic field enhancement were successfully fabricated and studied in the present work. The ZnO nanorods were grown on patterned substrate through hydrothermal process and the Au dimers were deposited on the top surface of ZnO nanorods, forming suspended gold dimer providing plasmonic hot-spots with nanocavity effect. Moreover, the Au/ZnO heterostructure could further enhance SERS signals with the chemical enhancement of ZnO to charge-transfer induced surface-enhanced Raman scattering. The effects of dimer radius, gap size and ZnO nanorod height on the dark-field scattering spectra and SERS were investigated experimentally and theoretically. The performance of fabricated substrates in SERS response was enhanced with increasing dimer radius, decreasing gap size and ZnO nanorod height at 200 nm. The enhancement factor of surface-enhanced Raman spectroscopy due to the localized surface plasmon resonance with different ZnO nanorod height was also calculated using finite-element time-domain (FDTD) method. The simulated EF as the functions of ZnO nanorod height showed the periodic trend of Raman intensity which was in agreement with the SERS response in experiments. In addition, the photocatalytic properties of Au/ZnO hybrid system were exploited through the degradation of probed molecules under UV-irradiation to demonstrate a reusable SERS-active substrate.
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