Reduction in Contact Resistance of Pentacene Thin-Film Transistors by Formation of an Organo-Metal Hybrid Interlayer

We propose a viable method of reducing the contact resistance of organic electronic devices by the formation of an organo-metal hybrid interlayer between a metal electrode and an organic semiconducting layer. The hybrid interlayer is produced by simultaneous deposition of the same materials as the electrode and the organic semiconductor, without any extra buffer layer. In such a hybrid interlayer, the metal clusters are uniformly dispersed on entangled organic surfaces so that they contribute significantly to the reduction of the contact resistance. The contact resistance is reduced by about a factor of seven. A simple theoretical model, based on the carrier accumulation and tunneling effects, well describes the essential features of the contact resistance as a function of the thickness of the hybrid interlayer. (C) 2009 The Japan Society of Applied PhysicsThis work was supported in part by Korea Ministry of Knowledge Economy through the System IC-2010 Project and by Samsung Electronics AMLCD. C.-J.Y. would like to acknowledge financial support from the research fund of Hanyang University (HY-2007000-0000-5932)