Electrical characterization of PEDOT:PSS

The purpose of this paper is to summarize the results of electrical measurements carried out on different types of metal-semiconductor heterojunctions based on PEDOT:PSS in order to examine the possibilities of either ohmic contacts or rectifying Schottky junctions formation. The character of created junctions was evaluated according to their I-V characteristics. Unusual electrical behaviour was observed in the case of heterojunctions formed on gold, platinum and carbon with a region of negative differential resistance. The phenomenon supposed to be partly responsible for such nonlinearity is existence of thin barrier layer on the surface of dried PEDOT:PSS, through which charge carriers could pass by tunneling. However, deeper investigation will be necessary to enlighten all the circumstances leading to origin of this behaviour.