Fabrication of core-shell structured poly(3,4-ethylenedioxythiophene)/carbon nanotube hybrids with enhanced thermoelectric power factors

Core-shell nanostructured poly(3,4-ethylenedioxythiophene) (PEDOT)/carbon nanotube (CNT) composites with high thermoelectric power factor have been successfully synthesized via a facile in situ chemical solution polymerization method. In this approach, the addition of sodium dodecyl sulfate (SDS) not only improves the dispersion of CNTs but also acts as soft templates to promote the ordered structure of PEDOT layer growing along CNTs. Raman spectra analysis confirms the existence of strong interfacial interaction between PEDOT and CNTs in such a core-shell nanostructure that facilitates charge transfer in the composites. As a result, an optimal power factor of 157 mu W m(-1) K-2 is achieved in PEDOT/CNT composite film, which is much higher than that of most reported PEDOT based composites fabricated by chemical solution polymerization method. Furthermore, the composites allow the fabrication of thermoelectric yarns via a simple dip-coating method. Textile-based thermoelectric generator based on segmented thermoelectric yarn that comprises 100 pairs of P-N junctions (p-type PEDOT/CNT composite yarns and n-type polyethyleneimine (PEI) doped PEDOT/CNT composite yarns) is assembled by embroidery of thermoelectric yarns into spacer fabric. The generator with high voltage output, good mechanical flexibility and air stability displays good potential as wearable power source. (C) 2019 Elsevier Ltd. All rights reserved.