Transparent Flexible Circuits Based on Amorphous-Indium-Gallium-Zinc-Oxide Thin-Film Transistors

Circuits implemented with high-performance amorphous-indium-gallium-zinc-oxide thin-film transistors (TFTs) are realized on polyimide/polyethylene-terephthalate plastic substrates. The TFTs on plastic exhibit a saturation mobility of 19 cm(2)/V.s and a gate voltage swing of similar to 0.14 V/dec. For an input of 20 V, an 11-stage ring oscillator operates at 94.8 kHz with a propagation delay time of 0.48 mu s. A shift register, consisting of ten TFTs and one capacitor, operates well with good bias stability. AC driving of pull-down TFTs gives the gate driver an improved lifetime of over ten years.