Free-Standing thermoelectric nanocomposite based on PEDOT:PSS, Cu 12+x Sb 4 S 13 , and MWCNTs

Abstract

Conductive polymers are promising for thermoelectric (TE) applications due to their lightweight, solution processability, and flexibility, yet their performance still lags behind that of inorganic semiconductors. Here, we report for the first time the fabrication of free-standing, flexible PEDOT:PSS-tetrahedrite (TH) nanocomposite films, further enhanced by multiwalled carbon nanotubes (MWCNTs). The tetrahedrite nanopowders were synthesized via a solvothermal method using 1-(2-aminoethyl)piperazine as the solvent, developed in our laboratory, offering an environmentally benign alternative to toxic or scarce TE fillers. The composite films were prepared by a simple drop-casting method and comprehensively characterized using XRD, FTIR, XPS, SEM, and TEM, while Scanning Thermoelectric Microscopy (SThM) enabled spatially resolved Seebeck coefficient mapping. The composite (20% nanoTH, 5% MWCNT) achieved a power factor of ~49.5 μW•m⁻¹•K⁻² at room temperature, representing more than a twofold improvement over optimized pristine PEDOT:PSS. Finally, a prototype thermoelectric generator validated the practical applicability of the best obtained material.