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.