Flexible, Freestanding Ternary Nanocomposite Thick Film of Polyaniline/WS2/CNTs for Efficient Thermoelectric Application

Conducting polymers are promising for near-room-temperature, wearable thermoelectric applications due to their flexibility, inherently low thermal conductivities, and tunable electrical conductivities. This work reports the fabrication of a flexible nanocomposite thick film consisting of conducting polymer, polyaniline (PANI), WS2 nanosheets, and carbon nanotubes (CNTs) and investigates its thermoelectric properties. The incorporation of WS2 nanosheets results in an ∼3 times enhancement in the Seebeck coefficient because of the high Seebeck coefficient of WS2 nanosheets and the energy filtering effect at the PANI–WS2 interface. The incorporation of CNTs acts as a conducting filler in the PANI/WS2 matrix, which helps in improving the mobility of charge carriers and enhances the electrical conductivity. Hence, the simultaneous incorporation of WS2 nanosheets and CNTs synergistically increases the Seebeck coefficient and the electrical conductivity in the nanocomposite thick films, which results in an ∼13 times enhancement in the power factor and an ∼10 times enhancement in the figure of merit (zT) at room temperature in comparison to pristine PANI film. The study suggests that the simultaneous incorporation of WS2 nanosheets and CNTs in PANI is a promising strategy to improve the thermoelectric properties of PANI-based materials.