Optimal Design And Application Research Of Perfect Absorber Based On Surface Plasmon Resonance

Based on the surface plasmon resonance effect,the design of metal nanostructure arrays can enhance the Raman scattering spectrum and increase the absorption of specific wavelengths.Therefore,SPR is widely used in low concentration molecular detection,biomolecular recognition,photovoltaic cells and electromagnetic wave control absorption and other fields.At present,the surface plasmon resonance of metal nanostructures is widely studied at home and abroad,but most of them are at the stage of basic mechanism research,and the preparation procedures of the samples are complex and can not be applied in large scale.In this paper,three kinds of periodic metal nanostructures are designed,which are easy to be prepared on a large scale.By changing the structure parameters and modulating the SPR effect,the SPR effect is strongest and the reflectivity is the lowest in a specific wavelength range.The optimal structural parameters are obtained by optimizing the parameters.Finally,the optimized structure parameters are prepared to explore the large-scale preparation process.The main work of this article is as follows:1.Controllable large-scale preparation and SERS effect of shell like perfect absorber.The periodic spherical shell structure based on polystyrene microspheres was prepared by nanospheres lithography technology.The PS microspheres were coated with spin coating method and then coated on a hexagonal tightly packed single layer structure to form a spherical shell array.The finite difference time domain algorithm is used to simulate the nanospherical shell structure.By changing the structure parameters,such as the thickness of the coating,the excitation of the SPR effect is controlled,the reflectivity of the specific band(wavelength 633nm)is the lowest.The film structure was prepared by three PS microspheres,430nm,520nm and 630nm.The thickness of the coating was 170nm,210nm,230nm,and gold coated on the single layer of hexagonal layer PS microspheres,forming a gold coated nano spherical shell structure.The morphology of the samples was characterized by scanning electron microscopy(SEM)and the reflectivity was characterized.Rhodamine 6G(R6G)was used as the probe molecule to carry out Raman spectrum test,and the enhancement multiplier was 180 times.The minimum reflectivity is less than 5%,which greatly reduces the reflectivity of gold film.2.Controllable large-scale preparation and SERS effect of triangular particle perfect absorber based on nanosphere lithography technology.The periodic nano spherical shell structure based on PS microspheres was prepared by NSL technology,and the microspheres were removed to leave the structure of triangular nanoparticles,and the thickness of the coating was 170nm,210nm and 230nm respectively.The morphology of the sample was characterized by SEM.Using R6G as the probe molecule,the enhancement ratio is 5-10 times.The electromagnetic field is simulated by FDTD,and the highest enhancement factor is about 105.It is found that the SERS substrate with a period of 520 nm,and a height of 230 nm has a good Raman enhancement effect under the irradiation of the excitation light with a wavelength of 633nm.3.Controlled large-scale preparation and optical absorption properties of porous alumina template filled silver nanowires.In this paper,porous alumiina template was prepared by one step method.The period,pore size and thickness of porous alumina template were changed by changing the oxidation voltage,oxidation time and concentration of oxidizing liquid during the process of processing.A variety of alumina templates were prepared.The SEM photo showed that it formed a periodic pore structure.The template is complete and has a high degree of order.The silver nanowires are deposited in the pores of the porous alumina template by alternating current electrodeposition,and the length and integrity of the silver nanowires can be controlled by changing the deposition time.Finally,the adjusted structure has a reflectance of about 5%.Through several different metal nanostructures,the application of SPR in light absorption enhancement and SERS was studied.The influence of structural parameters of different micro nano structures on the final absorption properties was explored.The preparation process of the film is studied,and the preparation process of the three structures is optimized,which can form a large scale preparation and lay a solid foundation for the later research.