Electrical Conductivity of Thin-Film Composites Containing Silver Nanoparticles Embedded in a Dielectric Teflon AF Matrix

TL;DR

This study investigates how the electrical conductivity of silver nanoparticle-embedded Teflon AF thin films varies with thickness and silver content, revealing percolation and metallic transition behaviors.

Contribution

It provides new insights into the percolation threshold and conductivity evolution in vapor-deposited silver-Teflon AF nanocomposites.

Findings

Conductivity increases with film thickness at moderate to high silver loadings.

Percolation occurs at silver content above 90%, forming a metallic continuum.

Conductivity plateaus at large thicknesses, indicating saturation.

Abstract

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.