Thermoelectric properties of the PEDOT/SWCNT composite films prepared by a vapor phase polymerization

•PEDOT/SWCNT composite films were prepared via a vapor phase polymerization method.•The thermoelectric properties of the composite films were measured.•The thermoelectric properties of the composite films are enhanced compared with pristine PEDOT.•The enhancement mechanism of the PEDOT/SWCNT films was proposed.

The poly(3,4-ethylenedioxythiophene)/single walled carbon nanotube (PEDOT/SWCNT) composite films with various SWCNT contents (0-50 wt.%) have been prepared by a vapor phase polymerization technique for the first time. The Seebeck coefficients of the composite films increase with the SWCNT contents. The maximum power factor is 37.8 μW mK−2 for a composite film with 35 wt% SWCNT, which is 1.7 times as high as that of the film without SWCNTs. The composite film with 35 wt% SWCNT has then been treated with a 0.04 wt% NaBH4/DMSO solution and the power factor increases to 44.1 μW mK−2 after the treatment. The PEDOT chains are more orderly arranged and with decreased doping level by forming composites with SWCNT and may be de-doped further after further treated with NaBH4/DMSO. Therefore, the Seebeck coefficient of the composite film has been further enhanced.