Letter: Solution-processed flexible zinc-tin oxide thin-film transistors on ultra-thin polyimide substrates

In this letter, solution-processed flexible zinc-tin oxide (Z0.35T0.65O1.7) thin-film transistors with electrochemically oxidized gate insulators (AlOx:Nd) fabricated on ultra-thin (30 µm) polyimide substrates are presented. The AlOx:Nd insulators exhibited wonderful stability under bending and excellent insulating properties with low leakage current, high dielectric constant, and high breakdown field. The device exhibited a mobility of 3.9 cm2/V · s after annealing at 300 °C. In addition, the flexible device was able to maintain the electricity performance under various degrees of bending, which was attributed to the ultra-thin polyimide substrate.