Solution-processible high-permittivity nanocomposite gate insulators for organic field-effect transistors

We report on solution-processible high permittivity nanocomposite gate insulators based on BaTiO3 nanoparticles, surface-modified with a phosphonic acid, in poly(4-vinylphenol) for organic field-effect transistors. The use of surface-modified BaTiO3 nanoparticles affords high quality nanocomposite thin films at large nanoparticle volume fractions (up to 37vol%) with a large capacitance density and a low leakage current (10−8A∕cm2). The fabricated pentacene field-effect transistors using these nanocomposites show a large on/off current ratio (Ion∕off 104–106) due to the high capacitance density and small leakage current of the gate insulator.