Absorption Of Hybrid Graphene/metamaterial Structures

Solar energy is an important way for human to obtain energy,and people have a wide range of demands for high efficiency and broad-spectrum absorbing materials.Since the separation of graphene in 2004,the scientific research on graphene has never stopped.Graphene is a kind of honeycomb two-dimensional material,which has unique mechanical,optical and electrical properties.It is one of the hot research topics to apply graphene to optical electronic devices by using these excellent physical properties.Based on the theory of plasmon,this paper aims to explore the performance improvement of graphene,a new two-dimensional material for plasmon devices,study the principle and physical characteristics of the surface micro nano structure optical device.Through the design and simulation,the performance improvement and physical characteristics of graphene/metamaterial hybrid optical absorber are studied.The main contents of this paper are as follows:The research background of plasmon and the basic properties of graphene,and the related research status at home and abroad are introduced.Next,the physical process and basic theory of metal plasmon generation,Drude model and dispersion relation are introduced.The conductivity model and dispersion relation of graphene plasmon are introduced,the principle of finite difference time domain method and boundary absorption condition are introduced.A solar absorber based on graphene/metamaterial is designed and simulated.The average absorption efficiency of the structure is 88.5%in the broadband range of 200 nm to 2250 nm,and it has three absorption peaks at 1098 nm,1927 nm and 2810 nm,respectively.The performance of the absorber is improved by 14.2%compared with that of the absorber without graphene layer.It continues to be excellent by changing the structural parameters,materials and microstructure shape Finally,the absorption of ASTM G173-03 solar spectrum is simulated.Based on the above structure,a second solar absorber with symmetrical structure is designed,and the average absorption efficiency is 1.2%higher than that of the first absorber.It has three absorption peaks at 1020 nm,1972 nm and 2845 nm,respectively.After optimizing the device parameters,a solar absorber with strong absorption for ASTM G173-03 solar spectrum is obtained.Finally,it is verified that the absorber is insensitive to the change of polarization and incident angle.