Research On Multiplex Controllable Assembly And Their Theoretical Study Of Metal Nanoparticles With Surface Plasmon

In surface plasmonic structures and devices photons can be manipulated and utilized in a nanometer scale and it has a high application value and scientific significance for the development of ultra-small,high efficiency optoelectronic devices,information storage,chemical and biological sensors,imaging,solar cells and other fields.The integrating of metal nanoparticles into optical electronic devices,will not only confine the light in nanometer scale,but also improve the capture efficiency of the incident light.At the same time,the surface plasmon resonance can be controlled by adjusting the structure of metal nanoparticles.Therefore,it has unique advantages and great potential in optimizing the structure and performance of the devices.At present,the structure with single metal nanoparticles can't meet the needs of interdisciplinary development.One of the key problems to develop a new type of highly integrated micro or nano-functional devices is the construction of multiple substrate with different metal nanoparticles on the surface(different sizes,different inter-particle distances,different shapes,etc.).However,there are still some difficulties in how to realize the construction of a precise,controllable,orderly and diversified functional substrate by simple and scalable method.The "top-down" micro/nano-fabrication technology,such as electron beam lithography,lithography,although can realize the precise control of metal nanoparticles in positioa However,due to its high cost,low yield,and can't achieve a large area of mass production,there is still a big obstacle to the actual production and applicationIn this paper,we start from the theory of electrostatic potential distribution on the surfece of the substrate.Through the coordination of the electrostatic potential on the surfece of the substrate and the colloidal particles,we can obtain a large area of two-dimensional assembly structure with metal nanoparticles.We have developed a new method for the ordered assembly of colloidal nanoparticles with gradient distances.So that we can get large area of diversified plasmonic structure.We have successfully constructed multi-functional surface structure with multiple response of surface plasmon resonance properties by combining the nano-imprint technique.It provides an effective way for the further development of high efficiency and super sensitive micro/na no-devices.The first chapter we introduce the finite element method far calculating the distribution of electrostatic potential by using PDE toolbox in MATLAB to solve Poisson equation.Deeply and systematically research on the electrostatic potential distribution of the SiO2 substrate with the variation of positive or negative charge and the amount of charge of a large area of two-dimensional structure or one-dimensional channel structure has conpleted.And we systematically explain the influence of the difference of the electrostatic potential distribution on the density and the spatial position of the particle assembly.In addition,we use simulation theory FDTD to study the effect of the variation of spherical particle size,distance,spatial arrangement,ambient refractive index and other shapes on the absorption,scattering,extinction spectra,reflectance spectra,transmission spectra,electromagnetic field intensity,current density and other parameters to reveal influence and mechanisms of the surface plasmon resonance coupling effect.In the second chapter,on the basis of the research on spacial electrostatic potential distribution,we have developed a new kind of gradient self-assemble method based on variation of the vertical spacial electrostatic inductioa By changing the thickness of PMMA to control the vertical distance between the gold nanoparticles and the SiO2 substrate,so that we can adjust the density of assembled gold nanoparticles by changing the size of the electrostatic force.We can achieve gradient inter-particle distance by gradually increasing the thickness of PMMA,and ultimately achieve the level of the single particle dark field imaging.The gold nanoparticles assembled on the PMMA film were successfully transferred by PDMS,and the multiple plasmonic structure was simply constructed.In the third chapter,a kind of multiple plasmonic structure containing 13nm and 30nm gold nanoparticle was initially constructed by nano-inprint lithography.And they are applied to the field of fluorescence enhancement,which provides a feasible scheme for the construction and development of the diversified structure.