Spectral Tuning of Plasmonic Absorption for High-Transmittance Nanostructured Metal Electrodes

Abstract

Networks of metal nanostructures are considered promising candidates for next-generation transparent electrodes. However, localized surface plasmon-mediated absorption at specific visible wavelengths limits their extensive use in a diverse range of photonic applications. This study proposes a strategy that spectrally tunes plasmonic absorption modes within periodic metal nanostructures with the aim of obtaining high-transmittance, transparent electrodes. A theoretical analysis of the periodic Ag nanostructures identifies localized surface plasmon resonances that have asymmetric (i.e., air-concentrated or substrate-concentrated) energy distributions due to the underlying substrate. The wavelength of a substrate-concentrated mode can be readily shifted by using a rationally designed dielectric spacer, which is leveraged to avoid plasmonic absorption at target wavelengths. A scattering analysis of a single Ag nanorod qualitatively supports the spectral tuning of plasmonic absorption modes. These theoretical findings will provide useful information for designing metal nanostructures for general transmission or absorption devices.