High Electrical Performance of Wet-Processed Indium Zinc Oxide Thin-Film Transistors

We developed thin-film transistors (TFTs) that use solution-processed amorphous indium zinc oxide for the channels in an all-photolithographic process. The transistors, which operate in depletion mode, have excellent transfer characteristics, including saturation mobility of 6.57 cm²/ V??s, threshold voltages of - 0.30 V, turn-on voltages of -1.50 V, on/off ratios of 10⁹, and inverse subthreshold slopes of 0.15 V/dec. We measured the time, temperature, gate voltage, and drain-voltage dependence of the threshold voltage shift, which was 2.16 V under stress conditions. This is nearly the same as that of conventional amorphous silicon TFTs.