Effect of PEDOT:PSS-molecule interface on the charge transport characteristics of the large-area molecular electronic junctions

Abstract

We have studied the effect of the PEDOT:PSS-molecule contact on the electrical characteristics of molecular junctions consisting of N-alkanedithiol and naphthalenethiol molecules. In this study, we experimentally investigated the properties of PEDOT: PSS-interlayer molecular junctions as they depended on the two kinds of PEDOT: PSS films (the pure PEDOT: PSS film and the dimethyl sulfoxide (DMSO)-modified PEDOT: PSS film) and their thermal annealing treatment. We observed that the electrical properties of these molecular junctions are influenced by the morphology and conductivity of the PEDOT: PSS films and by the thermal treatment. In particular, the resistance of the PEDOT: PSS-interlayer molecular junctions depended on the kind of PEDOT: PSS film and the temperature, within the range of elevated temperatures (higher than room temperature) tested. These experimental results are explained by the change of the interfacial properties of the PEDOT: PSS-molecule contact, which are influenced by the morphology change of the PEDOT: PSS film and the removal of residual DMSO or water from the interface. (C) 2012 Elsevier B.V. All rights reserved.