Fabrication of a layered nanostructure PEDOT:PSS/SWCNTs composite and its thermoelectric performance

Abstract

Layered nanostructure PEDOT:PSS/SWCNTs (single-walled carbon nanotubes) composites have been successfully prepared utilizing a method of two-step spin casting. SEM, FTIR and Raman were used to analysis the influence of the carbon nanotubes characteristics on the morphological, spectroscopic, electrical and thermoelectric properties of the composite materials. The layered nanostructure composites showed both improved electrical conductivity and Seebeck coefficient as compared to pure PEDOT:PSS, which could be attributed to the improvement of electron transport and phonon transport because of the bonding disruption of SO₃H group with the PSS chains and the use of quantum confinement and interface effects in layered nanostructures. The maximum electrical conductivity and Seebeck coefficient of the composites reached 241 S cm⁻¹ and 38.9 μV K⁻¹, respectively, and the maximum power factor could be up to 21.1 μW m⁻¹ K⁻², about 4 orders of magnitude higher than the pure PEDOT:PSS. This study suggests that constructing layered nanostructure organic–inorganic composites might be a novel and effective way for improving the thermoelectric properties of conducting polymers.