Study On The Light Absorption Properties Of Gold And Silver Core-Shell Nanostructured Metasurfaces

The principle of the metamaterial absorber is that when electromagnetic waves are irradiated on an object,the impedance of the object surface is matched with the free space by adjusting the structure shape,size,spacing and other parameters,which reduces the reflection and transmission of the object surface and realizes light absorption.Based on the surface plasmon resonance effect,absorption has been achieved in single band,dual band and ultra-wide bands in microwave,visible light,infrared,terahertz and other frequency bands.Its application in biomedical sensing,detectors,solar cells,etc.Be concerned.The current development trend of metamaterial absorbers is to design a simple,ultra-thin and high-efficiency adjustable single-band or ultra-wide-band metamaterial absorber.In this paper,based on the surface plasmon resonance effect,the light absorption properties of different gold and silver core-shell nanostructures are studied,and the finite difference time domain algorithm is used for numerical simulation to analyze the factors that affect the light absorption performance.Firstly,the super-surface structure model of the gold-silver core-shell nanocube faceto-face array was constructed,and the effects of mirror image,mirror layer thickness,dielectric layer thickness,particle spacing,silver shell thickness and incident light polarization angle on its light absorption performance were studied.Mirror image nearfield coupling can effectively increase absorption,and optimized parameters can achieve perfect absorption of dual bands in the visible light range.Secondly,the super-surface structure models of gold-silver core-shell nano cuboid super-surface,gold-silver core-shell nano-cylinder super-surface and gold-silver coreshell nanocube diagonal array super-surface were constructed,and the parameters affecting their light absorption properties were analyzed and studied.Finally,the light absorption properties of different gold-silver core-shell nanostructure supersurfaces are compared,and the light absorption properties of the goldsilver core-shell nanostructure supersurfaces are tunable,which provides a new direction for metamaterial absorbers in the visible light band.The shape,size,particle spacing and other parameters of the nanostructures can be artificially controlled to achieve precise control of the super-surface light absorption performance of the gold-silver core-shell nanostructures,and achieve perfect absorption of specific spectrum;by changing the structure of the array periodic unit,it can be achieved This provides a new idea for the realization of ultra-thin and adjustable absorbers,and at the same time has certain theoretical guiding significance for the development of new flexible materials.