發(fā)布時(shí)間：2018-03-19 09:26

  本文選題：表面等離激元　切入點(diǎn)：單晶銀盤　出處：《南京大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：表面等離激元(SurfacePlasmons,SPs)是由光照射在金屬表面而形成的一種自由電子集體振蕩模式。它在金屬表面亞波長范圍內(nèi)會產(chǎn)生非常強(qiáng)的束縛電場,表面等離激元的增強(qiáng)電場效應(yīng)使得其在表面增強(qiáng)拉曼散射(Surface enhanced Ramanscatterring,SERS)中得到應(yīng)用。而且伴隨微納米加工技術(shù)的不斷發(fā)展和改進(jìn),加工精細(xì)度和可控性得到優(yōu)化和提升,使得加工金屬納米結(jié)構(gòu)和SERS襯底的制備更加容易。本文主要從實(shí)驗(yàn)上用單晶銀盤做表面增強(qiáng)拉曼散射襯底,研究金屬表面等離激元在表面增強(qiáng)拉曼散射中增強(qiáng)效果。由于表面等離激元在金屬表面?zhèn)鞑r(shí)的損耗比較大,單晶銀盤是我們在樣品制備方面進(jìn)行的改進(jìn),以減少損耗,提高其SERS增強(qiáng)效果。我們在銀盤上設(shè)計(jì)了幾種周期性納米結(jié)構(gòu),能夠產(chǎn)生不同模式的表面等離極化激元,以及不同的電場分布,研究其SERS增強(qiáng)效果。1.介紹了單晶銀盤生長方法以及對其進(jìn)行了表征。我們利用化學(xué)液相生長法生長單晶銀盤,生長出來銀盤的直徑大小有數(shù)百微米,甚至一個(gè)毫米,厚度也達(dá)到幾個(gè)微米。我們用原子力顯微鏡測量表征銀盤表面的形貌及粗糙度,同時(shí)從實(shí)驗(yàn)上測量了金屬表面等離激元的傳播長度。2.我們先從理論上分析簡單一維光柵結(jié)構(gòu)光學(xué)性能,并用時(shí)域有限差分法(finite difference time domain,FDTD)模擬出光柵表面電場分布情況以及強(qiáng)度大小,優(yōu)化結(jié)構(gòu)參數(shù),以獲得較高的電場增強(qiáng)效果。實(shí)驗(yàn)上,我們在單晶銀盤上加工周期性納米結(jié)構(gòu),并測量了結(jié)構(gòu)的光色散譜,研究其光學(xué)性能。最后在其表面覆蓋一層單分子拉曼探針分子,得到比較好的拉曼增強(qiáng)效果,增強(qiáng)因子達(dá)到105～106。我們還研究了二維結(jié)構(gòu)的拉曼散射增強(qiáng)效果。
[Abstract]:The surface plasmon surface plasmonium (SPs) is a free electron collective oscillating mode formed by light irradiation on the metal surface. It produces a very strong binding electric field in the subwavelength range of the metal surface. The enhanced electric field effect of surface isoexcitators makes it widely used in surface-enhanced Raman scattering surface enhanced Ramanscatterring SERS. With the continuous development and improvement of micro-nano fabrication technology, the fineness and controllability of the surface are optimized and improved. It makes it easier to fabricate metal nanostructures and SERS substrates. In this paper, a single crystal silver disk is used as a surface-enhanced Raman scattering substrate. The enhancement effect of surface isoexcitons on surface enhanced Raman scattering has been studied. Because the loss of surface isotherms propagating on metal surface is relatively large, the single crystal silver disk is an improvement in sample preparation to reduce the loss. We have designed several periodic nanostructures on the silver disk to produce different modes of surface isobaric polaritons, as well as different electric field distributions. The growth method of single crystal silver disk and its characterization were introduced. We used the chemical liquid growth method to grow single crystal silver disk. The diameter of the silver disk was hundreds of microns or even one millimeter. The thickness is also several microns. We use atomic force microscopy to measure the surface morphology and roughness of the silver disk. At the same time, the propagation length of the isoexcitators on the metal surface is measured experimentally. Firstly, we theoretically analyze the optical properties of the simple one-dimensional grating structure. The electric field distribution and intensity on the surface of the grating were simulated by finite difference time-domain method (FDTD), and the structural parameters were optimized to obtain a higher electric field enhancement effect. In the experiment, we fabricated periodic nanostructures on a single crystal silver disk. The optical dispersion spectrum of the structure was measured and its optical properties were studied. Finally, a single molecule Raman probe molecule was coated on the surface of the structure, and a good Raman enhancement effect was obtained. The enhancement factor reaches 105 ~ 106.We also study the enhancement effect of Raman scattering in two-dimensional structure.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O614.122;O657.37
，

本文編號：1633658