Tuning the Threshold Voltage of Double-Gate Low-Voltage Transparent Oxide-Based TFTs by a Lateral In-Plane Gate

Double-gate low-voltage transparent oxide-based thin-film transistors (TFTs) with a lateral in-plane gate are self aligned by only one metal shadow mask. The threshold voltage of such devices can be tuned in a wide range from -1.07 to 0.78 V by the lateral in-plane gate, which allows the device switching from a depletion to an enhancement-mode operation. High performance with a field-effect mobility of >; 10 cm²/V · s, a current on/off ratio of ~3 × 10⁵, and a low subthreshold swing of ~195 mV/decade is obtained at various voltage biases of the in-plane gate. Such double-gate TFTs are promising for next-generation transparent electronics with low power consumption.