Deep-ultraviolet localized surface plasmon resonance using Ga nanoparticles

Localized surface plasmon resonance (LSPR) with Ga nanoparticles (NPs) was achieved and tuned over the entire deep-ultraviolet (DUV) wavelength range. Ga NPs with nano hemisphere structures were fabricated by combining vapor deposition and thermal annealing without top-down nanofabrication technology. We successfully fabricated Ga2O3 NPs by thermally annealing Ga NPs at high temperatures. The coating of Ga NPs with Al2O3 thin films prevented oxidation and improved the robustness of Ga NPs, which have a low melting point and are unstable at room temperature, enabling device applications. Furthermore, we fabricated a new NP structure with Ga or Ga2O3 located on Al mirror substrates, which can be applied to LSPR-enhanced light-emitting materials and devices. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement