Preparation of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)/silicon dioxide nanoparticles composite films with large thermoelectric power factor:

Herein, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/silicon dioxide nanoparticles (SiO2-NPs) composite films were prepared via a simple method by direct vacuum filtration technique. The effect of SiO2-NPs contents on the thermoelectric performance of PEDOT:PSS was investigated systematically. PEDOT:PSS nanofilm without SiO2-NPs exhibited a maximum electrical conductivity of 1487S cm(-1) and a Seebeck coefficient of 17.4 mu V/K. When the SiO2-NPs were introduced, the Seebeck coefficient of PEDOT:PSS/SiO2-NPs nanocomposite films increased to a peak value of 24.2 mu V/K at 20wt% SiO2-NPs, and the corresponding electrical conductivity was 1132S/cm. Although a compromise in electrical conductivity, a large optimized power factor up to be 66.29 mu W/m K-2 was achieved due to the contribution of improved Seebeck coefficient. The presence of SiO2-NPs in the composite films with small-size structure and abundant grain boundaries may cause the carrier scattering and filtering effect, which accounts for the enhanced Seebeck coefficient.