Transition Between Semiconducting and Metallic Behavior in PEDOT:PSS Composites

Highly conductive polymers have emerged as a leading candidate for future thermoelectrics. The addition of nanoparticles to conductive polymers has been shown to enhance electrical conductivity without a relative increase in thermal conductivity due to significant phase separation that scatters thermal carriers. Despite their enhanced thermoelectric performance, electrical transport in such composite materials is not well understood. By examining the nano and microscale morphology of PEDOT:PSS with Gold Nanoparticles (AuNP) we hope to connect the distribution of gold with the temperature dependence of bulk electrical transport. A transition is observed in the temperature dependent conductivity with AuNP volume fraction, from semiconductor-like behavior to metallic behavior, indicating a significant impact of the AuNP on the conductivity properties of the composite. Future work aims to compare this dependence with the effective medium model to determine optimal volume fractions for thermoelectric performance.