OPTICAL-PROPERTIES OF POLYMER LAYERS WITH SILVER PARTICLES

Composites consisting of small Ag particles embedded in near-surface r egions of viscous polymer (36 and 48 Pa s) were obtained by vacuum met al evaporation (4.8 x 10(-6) g/cm(2)). Such coatings taken at differen t polymer viscosities were a model substance simulating the properties of granular metal films produced in a solid by ion implantation. Aver age 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 l inear optical transmittance was measured from 300 to 900 nm. The optic al data were interpreted within the Bruggeman theory, which takes into account the dipole-dipole coupling among aggregated spheres. Agreemen t between theory and experiments was achieved by assuming a superposit ion of optical absorption of several thin layers with metal particles arranged at different depths from the polymer surface. (C) 1998 Elsevi er Science B.V.