Solution-Processable LaTiO_x-PVP as Silicon-Free Gate Dielectric at Low Temperature for High-Performance Organic-Inorganic Field Effect Transistors

We report that the organic-inorganic composite of polyvinyl phenol (PVP) and lanthanum titanate can be used as a gate dielectric layer of a low-voltage thin film transistor (TFT). The high-k organic-inorganic composite is synthesized at low temperatures through a solution-processable method and deposited by a simple spin-coating technology on polyethylene terephthalate coated by indium tin oxide (PET-ITO) film substrate. The fabricated devices show small and positive threshold voltage, and thus are applicable for low-power and high-speed operation. Thin film organic-inorganic composite transistors show high current on/off on order of 10⁴, dependent on composition. Organic-inorganic thin film transistors (TFTs) fabricated using composite of polyvinyl phenol and lanthanum titanate layers as gate dielectric and zinc oxide (ZnO) films as channel layers exhibit superior electron transport characteristics with the electron mobility of 1.04 cm² V⁻¹ s⁻¹, while the ratio of channel width (W) to channel length (L) for these devices is 20.