Electrical conductivity of thin-film composites containing silver nanoparticles embedded in a dielectric fluoropolymer matrix

Thin-film nanocomposites, consisting of silver nanoparticles embedded in a dielectric Teflon\textregistered AF matrix, were synthesized using vapor phase co-deposition. The electrical conductivity of these composites was measured in-situ as a function of film thickness at various metal concentrations. At low metal concentrations (<30%), dielectric behavior and very little change with film thickness was observed. At moderate to high silver loadings (30-80%) a large increase in electrical conductivity was observed as the films grew thicker. As the thickness increased further, the conductivity flattened out. At very high silver content (>90%), fragmented fractal nanoclusters were able to further interconnect to achieve the percolation process and eventually evolve into a metallic continuum with dielectric polymer inclusions.