title: Resonant SPP modes supported by discrete metal nanoparticles on high-index substrates.
abstract: We provide a new physical interpretation of scattering from plasmonic nanoparticles on high-index substrates. We demonstrate the excitation of different types of resonant modes on disk-shaped, Ag nanoparticles. At short wavelengths, the resonances are localised at the top of the particle, while at longer wavelengths they are localised at the Ag/substrate interface. We attribute the long wavelength resonances to geometric resonances of surface plasmon polaritons (SPPs) at the Ag/substrate interface. We show that particles that support resonant SPP modes have enhanced scattering cross-sections when placed directly on a high-index substrate; up to 7.5 times larger than that of a dipole scatterer with an equivalent free-space resonance. This has implications for designing scattering nanostructures for light trapping solar cells.
authors: Centre for Sustainable Energy Systems, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 0200, Australia. fiona.beck@icfo.es
authors: F J
authors: FJ
authors: Beck
authors: E
authors: E
authors: Verhagen
authors: S
authors: S
authors: Mokkapati
authors: A
authors: A
authors: Polman
authors: K R
authors: KR
authors: Catchpole