Plasmonic Structural Color Based On Metallic Nanostructure

Plasmonic structural colors originate from the interaction between light and metallic nanostructures.In recent years,the development in nanofabrication and characterization of plasmonic structures,including Focus Ion Beam(FIB),Electron Beam Lithography(EBL)and Nanoimprint Lithography(NIL),provides an efficient way to control light properties at subwavelength scale.Devices based on plasmonic materials have good performance in filtering and electrical response,which shows great potential of high-resolution devices,light controlling in real-time and other solar-thermal devices.For transmissive structural color,based on previous research,we try to improve the thickness of the structural color device.We couple the metallic nanogratings with freestanding silicon nitride membrane waveguide as our transmissive structural color filter.Our filter device has thickness of less than 200 nm,which is orders smaller than devices in previous researches.As experiments demonstrate,the fabricated free-standing plasmonic color filters have more than 70%transmission efficiency at different resonant wavelengths in the visible spectral region and are capable of generating arbitrary colors.Experimental results are in good agreement with the theoretical calculations.These artificial structural color filtering devices may find potential applications in high resolution color imaging and sensing systems.For reflective structural color,to generate a color of "absolute black",we propose a broadband tungsten absorber based on a nanocone metallic resonant structure fabricated by self-assembly nanosphere lithography.In experimental demonstration,the fabricated absorber has more than 93%average absorption efficiency and shows superior angular tolerance in the entire visible and near-infrared spectral region.In this reason,we can see the "absolute black" performance of our device.Furthermore,our proposed absorber shows perfect performance of angle tolerance and thermal stability.We envision that this large-scale nanostructured broadband optical absorber would find great potential in the applications of high performance optoelectronic platforms and solar-thermal energy harvesting systems.In all,we propose structural color devices based on metallic nanosturctures.With perfect performance and good practical tolerance,we envision these devices would be important in industrial applications.