Conclusions Evaluating scattering and near field properties of metallic and dielectric nanoparticles, we firstly found that the scattering cross sections can, in both cases, reach a value of several times the geometrical cross sections. For the dielectric nanoparticles, no parasitic absorption exists, whereas for the metallic ones, non-zero absorption cross sections are present, which however can be reduced by increasing the particle radius. The nanoparticle radius can be

BAY 80-6946 concentration used to tune the resonance position to the desired wavelengths. Scattering cross section maps, calculated here with Mie theory, give a fast overview of the parameter field and quickly show that dielectric nanoparticles with a refractive index around 2 require significantly larger radii (approximately 1.5 times) than metallic ones from, e.g., Ag in order to obtain similar resonance wavelengths. The electromagnetic near fields around the two different

nanoparticle types also significantly differ; whereas for the metallic nanoparticles, the field vanishes inside and builds up a strong localized field around the surface, the dielectric nanoparticles have strong fields inside, which however are not absorbed but preferentially scattered to the forward direction. These observations of both typical dielectric and metallic near-fields are found for semiconducting materials. On the one hand, they have a selleck inhibitor region of constant refractive index and zero absorption and thus a dielectric-like scattering behavior, but on the other Sodium butyrate hand, they can also show significant charge

carriers and thus metallic plasmon resonances. However, since the semiconductor also has a band gap and according high absorption for wavelengths below, it may only be of interest when the band to band absorption is outside the wavelength range in focus. Although semiconductors show the scattering properties of both dielectrics and metals, it was not possible to combine the two effects constructively. Depending on the application, one or the other type of material by itself may be preferred to a combination of both. Aside from the scattering ability and the near field distribution, also the angular distribution of the scattered light plays a crucial role for applications. Considering in particular the application to ultra-thin solar cells, both an enhanced near field and a particular scattering of the nanoparticle may contribute to enhance the absorption. In a homogeneous medium, the near field is stronger around the metallic nanoparticle, the scattering efficiency (scattering over scattering plus absorption) is stronger for A-1155463 in vitro non-absorbing dielectric nanoparticles, so that up to that point, no decision about the ideal choice of material can be made.