Optical properties of polymer layers with silver particles

Composites consisting of small Ag particles embedded in near-surface regions of viscous polymer (36 and 48 Pa s) were obtained by vacuum metal evaporation (4.8 x 10(-6) g/cm(2)). Such coatings taken at different polymer viscosities were a model substance simulating the properties of granular metal films produced in a solid by ion implantation. Average sizes of the spherical particles were 6 nm. The Ag particles were observed over a range of depths from the surface to about 60 nm. The linear optical transmittance was measured from 300 to 900 nm. The optical data were interpreted within the Bruggeman theory, which takes into account the dipole-dipole coupling among aggregated spheres. Agreement between theory and experiments was achieved by assuming a superposition of optical absorption of several thin layers with metal particles arranged at different depths from the polymer surface. (C) 1998 Elsevier Science B.V.