Exploring electrical conductivity within mesoscopic phases of semi-conducting PEDOT:PSS films by Broadband Dielectric Spectroscopy

Poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonic acid (PEDOT:PSS), an optically transparent organic semi-conductor, constitutes a suspension of conducting PEDOT:PSS grains, shelled by an insulating layer of PSS. While a percolation network enhances dc conductivity, structural and electrical inhomogenity hinters electric charge flow giving rise to capacitance effects. In the present work, two distinct relaxation mechanisms are detected by Broadband Dielectric Spectroscopy (BDS). Double polarization mechamisms are predicted by bi-phase suspension dielectric theory. Within the frame of interfacial polarization, we propose a methodology to have an insight into the local conductivity of the interior of mesoscopic conducting phase.