Organic thermoelectric films: achieving high conductivity and power factor through sulfonated-poly(3,4-ethylenedioxythiophene) and single-walled carbon nanotube composites

Abstract

The quest for sustainable energy solutions is critical amidst environmental challenges. Thermoelectric (TE) devices present a promising approach by converting waste heat into electricity through the Seebeck effect. These devices are advantageous due to their direct energy conversion, solid-state construction, reliability, scalability, long lifespan, and compatibility. However, their efficiency is often low, and they heavily depend on rare, expensive, and toxic inorganic materials. Carbon-based thermoelectric materials, such as carbon allotropes and organic thermoelectric materials such as conductive polymers, offer a sustainable alternative due to their abundance, low cost, eco-friendliness, and high mechanical flexibility, though their efficiency requires improvement. This study explores two generations of thermoelectric materials combining sulfonated-poly(3,4-ethylenedioxythiophene) (PSEDOT), a water-soluble and self-doped polymer, and single-walled carbon nanotubes (SWCNTs). The first generation optimized SWCNT dispersion and purification conditions, while the second generation improved the performance using better materials, resulting in a flexible film with a high conductivity (2000 S cm⁻¹) and a power factor of 96.8 µW m⁻¹ K⁻².