Two-dimensional grating structure implementation of SERS Substrate using two-step nanoimprinting process

• Main Authors: Wei-En Lu, 呂維恩
• Other Authors: Wen-Kai Kuo
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/d35h9z

碩士 === 國立虎尾科技大學 === 光電工程系光電與材料科技碩士班 === 104 === This study proposes using a commercially available fixed cycle master mold a one-dimensional grating as using a two-step nanoimprint way to produce a two-dimensional grating structures to produce surface-enhanced Raman scattering (SERS) substrate, and the two-dimensional raster rotate it lattice period approaching direction excitation wavelength of the excitation light of the strong alignment of the polarization direction of the surface to produce a surface plasmon polariton (SPP) to enhance the Raman signal. The substrate production, we use a commercially available 1800 lines / mm grating one-dimensional (a period of about 555 nm) as a master mold, reproduced a silicone mold having a one-dimensional grating benevolence, UV curing nanoimprint technology to imprint a dimensional grating on a glass substrate to control illumination dose, release when UV glue was semi-cured state, the substrate is rotated 90 degrees, then the mold core one-dimensional grating for a second imprint to produce two-dimensional raster structure, and finally a layer of gold deposited on the surface of the membrane to complete the SERS substrate production. In Raman signals measured using InPhotonics company''s fiber-optic Raman probes (Model: RPB fiber optic probe) with Ocean Optics spectrometers are Maya2000pro and wavelength 785 nm diode laser as the excitation source, we measured the system irradiating excitation light on the sample substrate elliptical polarization, greater light intensity in the direction of the long axis of the ellipse. We use the portion of the sample in a solution of benzoic acid to the solvent evaporation deposition method uniformly adhered to the two-dimensional grating substrate, then the substrate is placed on a rotating platform, rotating the substrate so that a two-dimensional lattice grating period nearly 785 nm (excitation wavelength) in the direction of elliptically polarized excitation light quasi-major axis, the strongest Raman signal can be obtained. Most simulation software we use EM Explorer excitation light of different polarization directions for generating an electric field to explore, to verify the results. Techniques presented in this thesis can be a low-cost way to create surface-enhanced Raman scattering substrate and produce the best signal enhancement Raman effect.