Low-temperature aqueous solution processed fluorine-doped zinc tin oxide thin-film transistors

Abstract

Novel fluorine-doped zinc tin oxide (ZTO: F) thin-film transistors (TFTs) have been fabricated using an aqueous solution process. Exploiting hydrolysis and condensation reactions in an aqueous solution process, organic-free ZTO: F thin films were fabricated at a low temperature of 250 degrees C. The fabricated TFT device shows a field-effect mobility of 2.85 cm(2)/V s, on-to-off current ratios exceeding 10(7), and sub-threshold swings of 0.83 V/dec. The ZTO: F TFT also displays high operational stability of Delta V-th = 1.73 V despite incorporation of a large amount of fluorine and use of a low-temperature annealing process. This is attributed to effective passivation of oxygen vacancy diffusion by metal fluoride bonds at the ZTO: F channel/gate dielectric interface.