Photoluminescence coupled to electric and magnetic surface lattice resonance in periodic arrays of zirconia nanoparticles

Abstract

Surface lattice resonance (SLR) is a collective resonance induced by radiative coupling between localized resonances in periodically arranged nanoparticles. Compared with metal nanoparticles, which have been conventionally utilized to realize SLRs, dielectric nanoparticles with a high refractive index and low absorption coefficient can achieve spectrally sharper resonances. Although titania (TiO₂) is a transparent material with a high refractive index and is used as a representative scatterer in the visible region, TiO₂ has absorption at energies higher than near-ultraviolet (UV). As an alternative to TiO₂, in this study, we fabricated periodic nanoparticle arrays composed of zirconia (ZrO₂), which is transparent in the near-UV region. ZrO₂ nanoparticle arrays are fabricated via the thermal oxidation of ZrN nanoparticle arrays and support SLRs of both electric and magnetic natures. As a demonstration, we examined photoluminescence (PL) enhancement of the emitter layer on the nanoparticle array. Compared with the TiO₂ nanoparticle arrays with identical design, the PL enhancement by the ZrO₂ nanoparticle arrays is larger under excitation with near-UV light, whereas it is comparable under visible excitation. These results indicate that ZrO₂ nanoparticle arrays are beneficial for applications involving light in the near-UV region.