Electrical Conductivity of PEDOT:PSS Film Prepared through Organic Compound Addition

Abstract

We report on the method of enhancement of the electrical conductivity of poly(3,4-ethylene dioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) films through a treatment with newly found organic additives, such as ethylene carbonate (EC) and ethylene sulfite (ES). Addition of these secondary dopants to PEDOT:PSS aqueous solution and subsequent film preparation resulted in conductivity enhancement by three orders of magnitude. Electrical resistivity of EC (3.1 mΩcm) and ES (2.9 mΩcm) added PEDOT:PSS films are comparable with previously reported secondary dopant, such as dimethyl sulfoxide (DMSO) (2.8 mΩcm). The temperature dependence of electrical resistivity of EC, ES and DMSO added PEDOT:PSS films indicates 3D-varible range hopping (VRH) conduction. Improving the electrical conductivity, however, we need to consider a crossover from VRH to metallic conduction at low temperature.