表面電漿效應之於銀奈米腔體之數值模擬與研究

本論文分為兩大主題：主題一: 奈米銀珍珠之表面電漿研究主題一利用有限元素法針對奈米銀珍珠陣列以及奈米銀殼珍珠對陣列，珍珠內部填充介電質材料研究它的表面電漿模式的效應，其模擬結果顯示奈米銀殼珍珠陣列以及奈米銀殼珍珠對陣列中間填充介電材料時，會顯示兩個表面電漿共振模這兩個共振模就是束縛模以及非束縛模，而這個現象是在奈米銀珍珠的同樣體積下所看不到的。主題二：奈米銀珍珠嵌入矽基板之表面電漿研究主題二利用有限元素法分析計算一個三維銀球結構嵌入二氧化矽基板，分別為奈米銀珍珠陣列與填入不同介質之奈米銀殼珍珠陣列來研究它的表面電漿模式的效應，其模擬結果顯示與topic 1所得知結果有顯著之差異，我們發現在奈米銀珍珠周圍具有侷域性場強，共振並不是單一奈米粒子的共振，而是由於dipole與嵌入介質基板互相作用，使得dipole共振強度有所不同。除此之外，映象電荷之效應也在topic 2中被討論。

關鍵字

有限元素法；表面電漿；束縛模及非束縛模

並列摘要

This thesis is divided into two topics: In topic 1, we numerically investigate the surface plasmon resonance (SPR) modes in periodic silver-shell nanopearl and its dimer arrays with the core relative permittivities filled inside the dielectric holes (DHs) by means of finite element method (FEM) with three-dimensional calculations. Numerical results of resonant wavelengths corresponding to the effects of different period of unit cells, radii of DHs, illumination wavelengths and the DH core relative permittivity of silver-shell nanopearls are reported as well. Simulation results show that silver-shell nanopearl arrays and its dimer arrays with DHs exhibit tunable SPR modes corresponding to the bonding and anti-bonding modes, respectively, that are not observed for the solid silver cases with the same volume. The boundary symmetry on the inner and outer surfaces of the silver nanopearl arrays with DHs can be broken by their structural and material parameters. It is shown that only the bonding mode can be excited at the lower core relative permittivity, whereas both the bonding and anti-bonding modes can be excited at the higher core relative permittivity. These results are crucial in designing localized SPR sensors and other optical devices based on periodic metal nanoparticle array structures. In Topic 2, we numerically investigate the SPR modes in periodic silver-shell nanopearl and its dimer arrays embedded with different depths in a substrate by means of FEM with three-dimensional calculations. The optical responses of embedding nanoparticles are quite different from that of the results obtained from Topic 1 due to the polarization effects in the substrate. In addition, the image charge which is similar to the effect of an electric charge has been discussed in topic 2 as well.