Optical properties of Ag-TiO2 nanocermet films prepared by cosputtering and multilayer deposition techniques

Ag-TiO2 nanocermet thin films, deposited for optical filtering applications by two sputtering techniques, codeposition and multilayer deposition, exhibit surface plasmon absorption in the spectral range 450-500 nm. The cosputtering technique induces a columnar growth, whereas multilayer deposition produces a more-random distribution of silver inclusions. Both films have large, flat silver grains at the air- cermet interface. An optical double-heterogeneous layer model based on the experimental morphological parameters of the films accounts well for their experimental transmittance, notably for extra absorption near 700 nm, which is attributed to a surface plasmon in the flat silver grains of the surface. (C) 2000 Optical Society of America OCIS codes: 160.4760,310.6860, 310.1620.