Low-Voltage Oxide-Based TFTs Self-Assembled on Paper Substrates With Tunable Threshold Voltage

Oxide-based thin-film transistors (TFTs) with a lateral in-plane electrode are self-assembled on paper substrates, and the electrical modulation effect of the in-plane electrode is investigated. A SiO₂-based solid-electrolyte film with high specific capacitance is used as the gate dielectric, and the operation voltage is reduced to less than 2.0 V. The threshold voltage (V_th) of such paper TFTs is tuned from -0.98 to 0.94 V by different voltage biases on the in-plane electrode. The threshold voltage shift (ΔV_th) can be described by ΔV_th = -(CG2/CG1)VG2, where CG2 and CG1 are the in-plane electrode and bottom-gate specific capacitance values. High electrical performance with a current on/off ratio of 6 ×10⁵ ~ 10⁶, a subthreshold swing of 0.14 ~ 0.19 V/dec, and a mobility of 8.64 ~ 9.45 cm²/V·s is obtained at different in-plane electrode voltage biases. Such low-voltage paper TFTs are promising for low-cost and portable electronics.