The application of silver oxide thin films to plasmon photonic devices

Silver has long been used for mirrors and tableware due to its high reflectivity, and it is still a very important component in optics. In particular, silver island films or small particles have been applied as photographic materials, tools and devices to generate localized electrical fields for molecular detection and electrical field enhancement. It has recently been discovered that silver oxide thin films may be a very useful material for dealing with optical near-field and surface plasmons. Silver oxide decomposes into oxygen and small metallic silver particles, and this characteristic has been applied to ultrahigh-density optical data storage to create a strong light-scattering centre that resolves small pits or marks beyond the diffraction limit. More recently, it has been found that silver film can be cheaply and easily transformed into Ag nanoparticles and nanowires in a gas mixture of hydrogen and oxygen in a vacuum chamber. The particle and wire diameters are very uniform and approximately 20–50 nm, and they can be three-dimensionally fabricated on almost all material surfaces without the need for thermal annealing. Silver nanoparticles and wires will soon appear in small and cheap molecular detection sensors by small precise adjustments for generating surface plasmon conditions.