Investigating the impact of nanoscale structures on thermoelectric transport in polymer-nanoparticle composites.

In solution-processed composite materials such as conducting polymers and nanoparticles, barrier-free thermodynamic phase separation can lead to the formation of interpenetrating continuous networks of components that exhibits a large chemically accessible interfacial area. Although theoretical and experimental results of some conducting polymer-nanoparticle composites have identified the importance of the physicochemical properties of the interface, models of electronic transport in these materials often neglect interfacial effects by using an effective-medium approximation to treat the interpenetrating material as combinations of individual parallel and series phases. We are improving these approximations by connecting the nanoscale structures of a model PEDOT:PSS and Au nanoparticle composite with macroscopic transport measurements of its electrical conductivity and Seebeck coefficient.