Contact resistance in organic thin film transistors

This letter reports on the unexpected dependence of contact resistance on the dielectric layer for pentacene thin film transistors with printed organic conducting electrodes. While the intrinsic mobility is weakly reliant on the dielectric, the contact resistance does vary considerably with dielectric layer. We show that while morphological changes are not apparent, contact resistances vary by an order of magnitude. This result suggests that the barrier to charge injection may depend not only on interactions at the complex triple interface but also on the details of the electronic structure at the semiconductor/dielectric interface. (C) 2004 American Institute of Physics.