Bottom-up fabrication of ordered 2D and 3D gold nanoparticle assemblies showing collective or individual plasmon resonances

The fabrication of plasmonic metamaterials mainly relies on top-down methods which allow for a precise control of their geometrical dimensions and consequently their optical properties. Chemical routes to plasmonic nanostructures are challenged by the required accurateness for well-resolved optical responses but allow for the generation of extended nanostructured areas. We report on a self-assembly approach for the fabrication of plasmonic metamaterials whose optical properties can be dictated either by individual or collective plasmon resonance of their building blocks. For this purpose wet-chemically synthesized gold nanoparticles are equipped with a polymer shell and self-assembled into ordered 2D or 3D structures using alternating spin-coating and plasma treatment cycles.