We report on organic field-effect transistors with enhanced gate effects using the soluble copolymer poly (vinylidene fluoride-trifluoroethylene) for the dielectric layer. The layer has a measured relative dielectric constant of about 11 (at 1 kHz) , which enables operation voltages smaller than for the organic insulator polymethylmetacrylate (epsilon = 3.3 at 1 kHz). (c) 2005 American Institute of Physics.