Electron beam induced modifications in electrical properties of Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) films

Conducting polymer PEDOT:PSS [Poly(3,4-ethylenedioxythiophene):poly(styrenesulphonate)], owing to its high electrical conductivity, enviornmental stability and low cost, is presently getting most attention for various device applications including thermoelectric, organic light emitting diodes and photovoltaics. We have investigated the irradiation effect of high energy electron beam on the electrical transport properties of PEDOT:PSS films to manifest the scope of this polymer in high radiation field and its suitability for radiation dosimeter applications. PEDOT:PSS films were deposited on flexible polyimide (Kapton) sheets using drop-cast method and irradiated up to 75 kGy dose with 1 MeV electron beam. The electrical conductivity of as deposited polymer film was ∼3.2 S/cm which consistently falls to ∼0.76 S/cm on irradiation dose of 75 kGy. Detailed characterization of the samples using x-ray photoelectron spectroscopy, contact angle measurement and solubility test conclusively suggested that the lowering of electrical conductivity in irradiated sample is attributed to the crosslinking of PEDOT chains and dissociation of PSS.