Optical properties of closely packed nanoparticle films: spheroids and nanoshells

We have developed an effective medium theory for the optical properties of nanoparticle films by considering the exact local fields of spheroidal nanoparticles on a substrate. The model allows the calculation of reflectivity, transmission and absorption of nanoparticle films for a wide range of filling factors, nanoparticle aspect ratios and substrate dielectric characteristics. It is suitable for many applications as it can treat films of homogeneous or binary core-shell nanoparticles