Study On The Surface Plasma Properties Of Metal-coated ZnO Nanostructures

The plasma plasmon oscillation of noble metal nanostructures is generated under the action of incident light,and the collision of free electrons will enhance the surface electric field.In addition,zinc oxide(ZnO)is a wide-band gap semiconductor material with excellent photoelectric properties.Combining noble metal nanostructure with ZnO material can further produce resonance coupling effect and broaden the application field of plasmon resonance properties,which has been one of the hot spots of researchers in recent years.Through a variety of performance tuning,noble metal nanostructures of surface electric field intensity is still cannot meet the actual demand,so the metal nanostructures localization,and semiconductor materials of dimers even polymer structure design offers a new way for the research of plasma effect,at the same time,the core-shell structure with dimer structure.It is very important to find an optimal structure in the model and explore the coupling effect between the core-shell nanostructures to improve the plasmonic resonance of materials.In this paper,the wave optical module of COMSOL Multiphysics software was used to establish the dimer and tetramer nanostructures with different parameters,and the mesh was divided by the finite element method,and then the multi-physical field distribution of the model was analyzed.Finally,the micro-mechanism of local surface plasmon resonance(LSPR)effect in different structures was discussed.The main research contents are as follows:(1)Several structural models of metal(triangle)@ metal(circle)dimer were established.The resonant frequencies were determined by studying the distribution of electric field intensity at different frequencies.The LSPR effects in Ag@Ag,Au@Au,Ag@Au and Au@Ag were compared under the same resonant frequencies.The results show that the Ag@Au structure in monolayer dimer has better LSPR properties with greater electric field enhancement.With Ag@ZnO and Ag@CuO in both metals @ semiconductor dimer structure model,the selection of the tablet is triangle @ circles,round and square @ circular shape model,such as different core-shell ratio on dimer structure is studied the influence of the electric field distribution,the results show that the Ag@ZnO core-shell dimer structure largely improves the field enhancement effect,It provides a new combination method for LSPR.(2)Based on the optimized parameters of Ag@ZnO dimer,circular and quadrilateral Ag monolayer tetramer and quad tetramer structures were established,and the electric field distribution of several structures and the dependence of the X component of electric field intensity on arc length were studied theoretically.The results show that the design of Ag@ZnO core shell tetramer structure improves the deficiency of single layer structure.It not only makes the electric field distribution along the axis of the axial symmetry,but also enhances the electric field intensity.Finally established a three-dimensional spherical four polymers,analyses the three dimensional four LSPR effect generated by the polymer structure,the results show that although in the 3D model can present the electric field enhancement of the situation,but it can't show the resonance coupling process,by changing the unit cell structure of the four polymers,can effectively regulate the formant of polymer structure and the intensity of resonance.(3)Ag coating ZnO with different structure model is established,the analysis of the metal shell and localized metal nanoparticles coated ZnO core-shell structure generate plasmons resonance enhancement effect,and studied the number of Ag particles(1,2,3,4)with different shapes(round,square,triangle)LSPR effect of ZnO nanostructures,Post-processing module using software to data processing of field intensity distribution and intensity of resonance,adjust and gradually optimized,thereby obtain the optimum refractive index,the optimum refractive index on the basis of further parameter optimization,the results obtained with the reported experimental results were analyzed,further filter out the most practical value of geometric parameters,summarize the theoretical simulation results,To explore the micro mechanism of local surface plasmon resonance characteristics of precious metal coated zinc oxide nanostructures.