Electrical and thermal properties of PEDOT:PSS films doped with carbon nanotubes

We report on a highly conductive polymer composite where poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is doped with dimethylsulfoxide (DMSO) and carbon nanotubes (CNTs). By the addition of single-walled CNTs (SWCNTs) into the DMSO-doped PEDOT:PSS solutions, the sheet resistance can be lowered from 279 Ω/□ to 150 Ω/□ without any compromise on the optical transmittance (81% at 520 nm) and surface morphology (∼2 nm). Through the measurement using Fourier transform infrared (FT-IR) spectrometer, it is found that the conductivity enhancement by the addition of CNTs is related to the bonding disruption of SO3H group with the insulating PSS chains. Furthermore, the enhanced thermal conductivity of the nanocomposite is demonstrated by its heat dissipation capability.