Visible Light Silver Nanoantenna on UV Responding Tin Nanoparticles

Abstract The plasmonic properties of metal nanoparticles have been extensively studied, not least because of their use in applications such as solar cells and other optical devices. A recent addition to the studies of plasmonic particles is the tin droplet, which is used to produce extreme ultraviolet (EUV) light by plasma formation after laser irradiation. This EUV light is used in the most advanced lithographic technology for resolutions down to ≈ 3 nm in integrated circuits. Controlling the plasmon properties of tin particles is therefore attractive for such technological applications. In this work, the localized surface plasmon resonance (LSP) of tin nanoparticles is modified by introducing a silver nano‐antenna at one side, effectively forming a Janus nanoparticle. As the LSP of the silver nanoparticle antenna is active in the visible light domain, the LSP of tin, which is located more in the ultraviolet (UV) range, can be complemented with more favorable plasmonic response energies. With electron energy loss spectroscopy (EELS), the surface and bulk plasmon resonances of this tin‐silver nanocomposite particle are studied, which forms a first step in precise tailoring of LSP properties, up to EUV energies.