High energy electron beam induced improved thermoelectric properties of PEDOT:PSS films

The tailoring of electrical conductivity and thermoelectric properties of conducting polymer through chemical dopants is an important area of research. However in the present work we demonstrate that the exposure of PEDOT:PSS films to high energy electron beam to improve its thermoelectric properties. The electron beam treatment of the films was carried out with 10 MeV RF accelerator by delivering dose up to 75 kGy in steps. The electrical conductivity was found to enhance linearly while the Seebeck coefficient systematically decreases with increasing dose up to 25 kGy and over all power factor improves till 10 kGy. In depth characterizations using PL, UV–Vis, FESEM, XPS, FTIR and Raman spectroscopy revealed that on irradiation the losses of PSS units and associated structural modifications along with increase in oxidation level of PEDOT component are responsible for improved conductivity and lowering of Seebeck coefficient. The study also highlights the utilization of flexible and simply prepared PEDOT:PSS thin films as potential radiation dosimeter based upon linear rise in electrical conductivity with increasing dose of electron beam.