Near-IR plasmons in micro and nanoparticles with a semiconductor core

We computationally study the electromagnetic response of semiconductor micro and nanoinclusions for realizing highly reflective, plasmonically enhanced coatings in the visible and infrared regime. We first examine the influence of oxide coatings on the Mie resonances of microparticles of low-bandgap semiconductors (Si and Ge) in the near-IR regime. We then study the influence of a semiconducting core on the localized surface plasmon resonances of Si@Ag and Ge@Ag core@shell nanoparticles. Our results show a strong interaction between the resonances of the plasmonic Ag shell and the semiconducting core material which allows tuning of the electromagnetic response for near-IR applications.