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dc.contributor.advisor Lazarides, Anne A en_US
dc.contributor.advisor Smith, David R en_US
dc.contributor.author Chen, Shiuan-Yeh en_US
dc.date.accessioned 2011-06-09T12:59:06Z
dc.date.available 2012-06-02T04:30:08Z
dc.date.issued 2011 en_US
dc.identifier.uri http://hdl.handle.net/10161/3904
dc.description Dissertation en_US
dc.description.abstract <p>The electromagnetic properties of various plasmonic nanostructures are investigated. These nanostructures, which include random clusters, controlled clusters and particle-film hybrids are applied to surface-enhanced Raman scattering (SERS). A variety of techniques are utilized to fabricate, characterize, and model these SERS-active structures, including nanoparticle functionalization, thin film deposition, extinction spectroscopy, elastic scattering spectroscopy, Raman scattering spectroscopy, single-assembly scattering spectroscopy, transmission electron microscopy, generalized Mie theory, and finite element method. </p><p>Initially, the generalized Mie theory is applied to calculate the near-field of the small random clusters to explain their SERS signal distribution. The nonlinear trend of SERS intensity versus size of clusters is demonstrated in experiments and near-field simulations. </p><p>Subsequently, controlled nanoparticle clusters are fabricated for quantitative SERS. A 50 nm gold nanoparticle and 20nm gold nanoparticles are tethered to form several hot spots between them. The SERS signal from this assembly is compared with SERS signals from single particles and the relative intensities are found to be consistent with intensity ratios predicted by near-field calculation.</p><p>Finally, the nanoparticle/film hybrid structure is studied. The scattering properties and SERS activity are observed from gold nanoparticles on different substrates. The gold nanoparticle on gold film demonstrates high field enhancement. Raman blinking is observed and implies a single molecule signal. Furthermore, the doughnut shape of Raman images indicates that this hybrid structure serves as nano-antenna and modifies the direction of molecular emission. </p><p>In additional to the primary gap dipole utilized for SERS, high order modes supported by the nanoparticle/film hybrid also are investigated. In experiments, the HO mode show less symmetry compared to the gap dipole mode. The simulation indicates that the HO modes observed may be comprised of two gap modes. One is quadrupole-like and the other is dipole-like in terms of near-field profile. The analytical treatment of the coupled dipole is performed to mimic the imaging of the quadrupole radiation.</p> en_US
dc.subject Engineering en_US
dc.subject Physical Chemistry en_US
dc.subject Optics en_US
dc.subject Nanoparticle en_US
dc.subject Near field en_US
dc.subject Scattering en_US
dc.subject Surface-enhanced Raman scattering en_US
dc.subject Surface plasmons en_US
dc.title Control of Surface Plasmon Substrates and Analysis of Near field Structure en_US
dc.type Dissertation en_US
dc.department Electrical and Computer Engineering en_US
duke.embargo.months 12 en_US

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