Summary: | 碩士 === 國立成功大學 === 物理學系碩博士班 === 100 === The surface plasmon is a phenomenon observed when the electronic cloud outside the metallic nanoparticles was stimulated by incident light. Plasmon resonance can result in huge magnification of the local field at the metallic surface which can conquer the optical limitation and improve the spatial resolution of detection. The surface plasmon only enhances the molecular signal near the metallic nanoparticles; therefore the property can be applied in surface-enhanced Raman spectroscopy (SERS).
In this study, we used different patterns with gold nanoparticles on BiFeO3 to discuss the influence of surface-enhanced Raman spectrum. In our experiment, due to laser wavelength is 532 nm in our laboratory, we used chemical methods modifying the component, size and shape of nanoparticles to adjust the surface plasmon band (SPB) around 532 nm in order to achieve the best surface plasmon requirement. Then we use Atomic Force Microscopy (AFM) to perform lithography technique to control surface charges on the multiferroic material BiFeO3. Through the positive charge on BiFeO3, we immersed the sample into the Au nanoparticles (AuNPs) solution to attract the nanoparticles which have negative charges outside. We use this technique to perform the different AuNPs patterns on BiFeO3 to investigate the influence of surface-enhanced Raman spectrum.
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