Effects of annealing temperature on electrical characteristics of solution-processed zinc tin oxide thin-film transistors

We investigated the effects of annealing temperature on the electrical characteristics of solution-processed zinc tin oxide (ZTO) thin-film transistors (TFTs). When the annealing temperature increased from 300 to 500 °C, the threshold voltage of solution-processed ZTO TFTs decreased from 16.89 to -0.23 V owing to the increase in electron concentration in the active layer. The increase in electron concentration is caused by the decrease in Cl atomic concentration. When the annealing temperature increased to 500 °C, the saturation mobility increased from 0.18 to 4.75 cm ².V ^-1.s ^-1 and the threshold voltage shift for positive gate bias stress as a reliability characteristic decreased from 5.34 to 2.6 V, because of the decomposition of halide residues such as Cl and the nanocrystallization.