Interpenetrating polymer network dielectrics for high-performance organic field-effect transistors

We have demonstrated the preparation of interpenetrating polymer network (IPN) dielectrics for use in high-performance organic field-effect transistors by blending commercially available polymers (PMMA, PtBMA, and PS) with the crosslinkable polymeric silsesquiazane (SSQZ). This facile blending method is a powerful means of enhancing the electrical strength of polymer dielectrics due to the formation of a siloxane network structure interspersed among the polymer chains. We found that the leakage currents for the PMMA and PtBMA gate dielectrics blended with SSQZ significantly decreased, by as much as two orders of magnitude, compared with the pristine cases. These remarkable enhancements in the dielectric properties arose from decreases in the free volume and in the thermal dynamic motions of the polymer chains due to formation of the polysiloxane network. The IPN gate dielectrics provide a facile method for using commercially available polymers to fabricate polymer gate dielectrics with strong electrical strengths.