Flexible InGaZnO thin film transistors using stacked Y₂O₃/TiO₂/Y₂O₃ gate dielectrics grown at room temperature

In this Letter, we report a low operation voltage and high mobility flexible InGaZnO thin-film transistor (TFT) using room-temperature processed Y₂O₃/TiO₂/Y₂O₃ gate dielectric. The flexible IGZO TFT showed a low threshold voltage of 0.75 V, a small sub-threshold swing of 137 mV/decade, a good field effect mobility of 32.7 cm²/V s, and a large I_on/I_off ratio of 1.7 × 10⁶. The low operation voltage, small sub-threshold swing and high mobility could be ascribed to the combination of high-κ TiO₂ and large band gap Y₂O₃, which provide the potential to meet the requirements of low-temperature and low-power portable electronics.