Thermoelectric devices consist of solid state materials that enable the direct conversion of thermal energy to electricity. In a working module, they require both n-type and p-type materials to be connected electrically in series, while being thermally in parallel. The performance of these materials is typically discussed in terms of a dimensionless figure of merit, ZT=S2σκ-1T, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the temperature. Hybrid thermoelectric devices based on conducting polymers and chalcogenide-based nanostructures have been proposed due to the intrinsic low thermal conductivity of the polymer, in addition to pursuing nanostructuring as a means of further improvements via phonon scattering. These hybrid materials systems also offer advantages related to their solubility characteristics, which offer a route towards low cost, solution processable applications. While some work has been done in this context, most of the resulting composite materials are p-type, owing to difficulties in n-type doping of conducting polymers, and the nature of the applied nanocrystals, and there is a strong drive to compliment the advances in hybrid p-type materials with new n-type materials. Herein, we report a template-based synthesis for n-type hybrid materials based on Ag2Te encapsulated in PEDOT:PSS. We are able to directly control the stoichiometry of our Ag2Te during synthesis, and find that we are able to effectively tune the hybrid material from p-type to n-type. Along with developments in the electronic properties, we also follow how different synthetic conditions influence the resulting morphology, which we then relate to the thermoelectric performance. We aim to show how these changes in the structure and composition relate to the thermopower and electrical conductivity in an effort to guide performance improvements in these and related hybrid material systems.

Synthetic manipulation of hybrid thermoelectric materials

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.