Tuning thermoelectric performance of Poly(3,4-ethylenedioxythiophene): Poly (styrene sulfonate)/Polyaniline composite films by nanostructure evolution of polyaniline

Abstract

The relation of molecular structures, morphologies, and thermoelectric (TE) properties of the poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate)/polyaniline (PEDOT: PSS/PANi) composite films have been carefully investigated. Various nanostructured PANi were synthesized firstly. Then PEDOT: PSS were employed to prepare PEDOT: PSS/PANi composite films. The morphological and structural characterization reveal that PANi nanoflakes with planar molecule structure possess the most ordered chain stacking, resulting good crystallinity and the highest TE properties in PEDOT: PSS/PANi-nanoflakes composite films. The power factor of PEDOT: PSS/PANi composite films increases as follows, PEDOT: PSS/PANi-hollow spheres < PEDOT: PSS/PANi-nanotubes < PEDOT: PSS/PANi-nanoparticles < PEDOT: PSS/PANi-nanowires < PEDOT: PSS/PANi-comb-like sheets < PEDOT: PSS/PANi-nanoflakes. It was found that in PEDOT: PSS/PANi, the π-bonded surface of PEDOT induce PANi to arrange regularly along the PEDOT sheets, and enriched PEDOT-PANi region enhance the electrical conductivity of PEDOT: PSS/PANi films.