Flexible Dual-Gate Oxide TFTs Gated by Chitosan Film on Paper Substrates
Low-voltage flexible dual-gate indium-tin-oxide-based thin-film transistors (TFTs) are self-assembled on SiO<sub>2</sub>-covered paper substrates by one shadow mask diffraction method. Solution-processed chitosan gate dielectric films have a large gate specific capacitance (5.8 μF/cm<sup>2</sup>) due to the electric-double-layer effect. The subthreshold swing, drain-current on/off ratio, and field-effect mobility are estimated to be 80 mV/dec, 4 ×10<sup>6</sup>, and 9.3 cm<sup>2</sup>/V·s, respectively. Low-voltage operation mechanism and threshold voltage modulation of such dual-gate paper TFTs are investigated.