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.