Fabrication and characterization of ZnO nanowire transistors with organic polymer as a dielectric layer

Single-crystalline wurtzite ZnO nanowires were synthesized and used to fabricate field-effect transistors, using poly(4-vinyl phenol) polymer as a dielectric layer. The spin-coated, thin (120 nm) PVP layer exhibited quite a good dielectric behaviors, such as dielectric strength of ∼1.5 MV/cm (∼10^-7 A/cm²), capacitance of 28.9 nF/cm², and dielectric constant of ∼3.93. When compared to the bottom-gated ZnO nanowire devices with thermal SiO₂ as a gate dielectric, the top-gated devices with the polymer dielectric showed much higher (∼5 times) mobility. This hybrid approach, i.e. inorganic single-crystalline semiconducting nanowires with organic polymer dielectrics, is shown to be promising for the nanowire-based devices to mechanically flexible applications.