All solution-processed amorphous oxide thin-film transistors using UV/O3 treatment

In the fabrication of amorphous oxide thin-film transistors (TFTs) by all-solution process, an ultraviolet–ozone (UV/O3) treatment and solution materials were adopted. By applying the UV/O3 treatment for solution-processed In2−xGaxZnO4 channel layers, enhancement of TFT characteristics was achieved. In particular, the most appropriate metal composition for the In2−xGaxZnO4 system with UV/O3 treatment was found to be x = 1.0. In addition to the channel layers, solution-processed LaNiO3, Bi–Nb–O/La–Ta–O stacked layer, and ITO films were formed as the gate electrode, gate insulator, and source and drain electrodes, respectively, for TFT fabrication. Using UV/O3 treatment and solution materials, all-solution-processed amorphous oxide TFTs were successfully fabricated, and superior TFT properties, including an on–off current ratio of 107, a threshold voltage of 1.6 V, a subthreshold swing of 200 mV/decade, and a field-effect mobility of 0.49 cm2 V−1 s−1, were achieved.