Tunable Localized-Surface-Plasmon-Resonance Characteristics of Independently Prepared Ag-TiO₂ Particles

Abstract

Ag and TiO₂ particles prepared by the evaporation-condensation method and spray pyrolysis, respectively, were mixed in N₂ gas flow, and then deposited on the SiO₂ glass substrate to form a film. Optical properties of the film thus obtained were evaluated using UV-Visible spectrophotometer and Z-scan technique. As a result, the absorption peak wavelength of Ag particles due to localized surface plasmon resonance (LSPR) was shifted toward longer wavelength side with increasing the concentration of Ti(OC₃H₇)₄ used as a starting material of TiO₂ particles. This indicates that LSPR peak of Ag particles is strongly influenced by TiO₂ particles. Therefore, this method is useful to develop tunable LSPR devices such as optical switches and sensors. Meanwhile, nonlinear refractive index determined by Z-scan technique was negative. [DOI: 10.1380/ejssnt.2006.566]