Optical study of Ag-TiO2 nanocermet thin films prepared by RF co-sputtering

The optical properties of Ag-TiO2 nanocermet thin films are studied with th e aim of optical filtering applications. Beyond the classical properties of cermets with noble metal inclusions predicted by the effective medium theo ries, the optical properties of Ag-TiO2 nanocermets deposited by R.F. cospu ttering are governed by their columnar morphology and the under-stoichiomet ry of the TiO2 matrix. A careful experimental analysis of the different par ameters and effects involved in the optical response of these nanocermets i s performed both on TiO2 and Ag-TiO2: film thickness, silver volume fractio n, thermal treatments, oxidation. The influence of these parameters on the surface plasmon resonance and the infrared transmission of the nanocermet t hin films is optimized.