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

Abstract

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 37 vol %) with a large capacitance density and a low leakage current (10⁻⁸ A/cm²). The fabricated pentacene field-effect transistors using these nanocomposites show a large on/off current ratio (I on/off 10 ⁴- 10 ⁶) due to the high capacitance density and small leakage current of the gate insulator.