The Fabrication Of Ordered Nanostructures By Mask Method

When the material is at the nanometer level,it will show the completely different properties and behavior from the macro-scale material.Noble metal nanostructures have attracted wide attention due to their unique optical properties,thanks to the surface plasmon resonance surface.The resonance strongly depends on the shape,size,composition and surrounding dielectric environment of the nanostructures.When the nanoparticles are excited at their resonant wavelengths,the strong absorption and scattering of the incident light will increase.Based on the SPR property of the noble metal nanostructures,it has shown value in small optical devices,sensing,optical communication,drug diagnosis and treatment.With the development of chemistry synthetic and micro-printing technology,noble metal nanostructures and materials with different sizes and morphologies has been fabricated.How to more simple,fast,and low-cost to fabricate noble metal nanostructures and tune optical properties has attracted lots of interest.In this paper,metal nanostructures with different morphologies were fabricated by mask method,and study the corresponding optical properties which can be applied in many applications.In the second chapter,we used the mask method to construct the highly ordered nanostructure array with different morphologies.The method is simple,controlled and can achieve a large area of ordered nanostructures.First of all,after HF etching the glass substrate,we successfully transferred the gold porous membrane mask to an arbitrary substrate which reducing the wrinkling and crash resulting from the transfer process to a large extent.Secondly,the mask method can fabricate long-range ordered nanostructure with various shapes utilizing the same template.The period and size of the nanostructure array can be controlled by changing the period of the PS microsphere and the length of the etching time.In addition,the mask method can be easily combined with different materials to fabricate complex nanostructure(Au,Ag,Al,Pt,Pd,SiO2)that can be applied to the chemical and biological sensor,nanoantenna,enhanced optical substrate.In the third chapter,we utilized the gold porous film as mask to fabricate highly ordered nanostructures: Ag nanodiscs array,Ag nanopillars array and Ag nanocrescents array.By changing the etching time,nanodiscs and nanopillars with different size were prepared.With the increase of the etching time,the structure size gradually decreased and the resonance absorption peaks were blue-shifted.In addition,changing the etch time and thermal deposition angle of the noble metal material can prepare the dimer nanocrescents with different size and study the effect of parameters on optical properties.The fabrication of ordered nanostructures with different morphologies and studying their optical properties provided potential applications for nanostructures in the fields of sensors,enhanced spectroscopy and negative refractive materials.