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The influence of nanometric surface morphology on surface plasmon resonances and surface enhanced effects (SERS) of metal nanoparticles Abstract: Plasmonics is a booming field with numerous applications ranging from optical data processing over negative-refraction materials to bio-sensors. Concerning better tuning and understanding of the plasmonic effect, two major roadblocks deserve a deeper study: 1. the strong plasmon damping in metals, 2. the huge gap between theoretically predicted and experimentally determined real-life samples. In the case of surface enhance effects (SEE) as SERS, chemically prepared and deposited metal colloidal particles are usually very efficient substrates, their disadvantage lying in the random nature with regard to particle size and shape, as well as to particle arrangements. The alternative approach to get well-controlled, reproducible substrates is e.g. electron beam lithography (EBL). This technology's drawback is the considerable surface roughness on lithographic samples. The surface roughness itself is supposed to play an important role, evidenced from the comparison between lithographically fabricated nanostructures with the crystallographically better defined chemically synthesized particles, revealing a drastic impact of crystallinity and surface morphology on the optical properties. In this work, an addressing of the effects caused by surface roughness by a systematic comparison between lithographically fabricated nanostructures and chemically synthesized ones is attempted, including the investigation of single and ensemble of particles supported by detailed theoretical model calculations. |