Oxide-Based Electric-Double-Layer Thin-Film Transistors on a Flexible Substrate

Flexible electric-double-layer (EDL) InGaZnO thin-film transistors (TFTs) were fabricated on a plastic substrate at room temperature. A large ED' gate capacitance, 0.22 μF/cm 2 , at 20 Hz was achieved using 200-nm-thick radio frequency magnetron sputtered porous SiO 2 as the dielectric layer, which is equivalent to ~15.7-nm thermally grown SiO 2 . The devices, therefore, show a low operating voltage of 1 V, a high current ON-OFF ratio > 10 5 , and a low subthreshold swing