Changing electrical properties of PEDOT:PSS by incorporating with dimethyl sulfoxide

Highlights: • Dimethyl sulfoxide (DMSO) is incorporated into PEDOT:PSS samples. • The doping mechanism for DMSO-doped PEDOT:PSS samples is investigated. • The incorporation of DMSO leads to an increase in conductivity of PEDOT:PSS. • The increased mobility is mainly due to the reduced electron-phonon coupling. • The increased carrier density is due to a high affinity of DMSO for water. The effect of incorporation of dimethyl sulfoxide (DMSO) into poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on the electrical conductivity is investigated. It is shown that the values of the carrier mobility and the carrier density increase significantly for PEDOT:PSS films with DMSO addition. The high carrier mobility of PEDOT:PSS samples with the addition of DMSO is attributed to a combined effect of the modification of the electron-phonon coupling and a change in the value of the PSS-to-PEDOT ratio. The high carrier density of PEDOT:PSS samples with DMSO addition is attributed to a high affinity of DMSO for water.