Growth And Optical Properties Of Single Crystal Silver Disk

Surface plasmon means that when the light incident to the interface between the metal and the dielectric,the photons are coupled to the free electrons on the metal surface to form a special electromagnetic oscillation mode,which is divided into surface plasmon polaritons and local surface plasmon resonance.SPP can propagate along the metal surface,but due to ohmic loss,the propagation distance is about 10 microns.However,compared with polycrystalline,monocrystalline materials can reduce the loss of SPP in the propagation process due to its superior performance.By designing subwavelength structure,we can bind the SPP in the sub wavelength range,strengthen the field,and have a wide range of applications in the fields of enhanced fluorescence and enhanced Raman.In this paper,a large size single crystal silver disk was developed and characterized by wet chemical method.After that,the "?" shaped structure was processed on the single crystal silver plate and polycrystalline silver film as SERS substrate,and the difference in the effect of Surface enhanced Raman scattering(SERS)on the single crystal and polycrystal was compared.The main contents are as follows:1.introduction:briefly introduce the principle of surface plasmon and Raman scattering,and review the recent progress in enhanced Raman spectroscopy.2.material growth:the growth method and morphology characterization of single crystal silver plate are introduced.The silver platter produced by this method is usually in the hundreds of microns,even to a millimeter,and the thickness varies from several microns to tens of microns.The morphology was characterized by scanning electron microscopy and atomic force microscopy.3.Raman performance:first,we do numerical simulation of the "?" shaped structure to get the dispersion relation of the structural parameters,and guide the experiment to process the "?" shaped structure of the optimal parameters.In the experiment,a silver film and a single-crystal silver plate were used.The optical properties of the structure were studied by measuring the reflectivity and SERS properties to compare the superiority of the single crystal material and polycrystalline.