Plasmonic response of metallic nanoparticles embedded in glass and a-Si

The optical properties of nanoparticle (NP) metals displaying the highest plasmonic response (silver, gold, copper and aluminium) are simulated. Embedding the metal NPs in a dielectric medium provides prevention from agglomeration, increased absorption and protection from environmental effects. Hence, embedding is an effective method to improve the performance of plasmonic-based devices. The NPs of the aforementioned metals were simulated in air, glass and a-Si environment from the ultraviolet to the near-infrared range. Spheres, nanobars and nanoprisms of volume equal to spheres of diameter 50–200 nm were studied in a broad wavelength range of 200–1800 nm. The effect of the material, size, shape and environment was observed quantitatively by analysing the peak shifts of the dipole and higher-order poles. The highest extent of peak shift due to change in size and surrounding environment was for aluminium, followed by silver, gold and copper.