High-performance low-temperature solution-processed InGaZnO thin-film transistors via ultraviolet-ozone photo-annealing

Ultraviolet (UV)-ozone photo-annealing was applied to fabricate low-temperature high-performance solution-processed thin-film transistors (TFTs). With UV-ozone treatment at the optimal temperature of 300 °C, TFT devices showed an improved field-effect mobility of 1.73 cm2 V−1 s−1, a subthreshold slope (S) of 0.32 V dec−1, an on/off-current ratio greater than 1.3 × 107, and good operational bias-stress stability compared to those of InGaZnO TFT devices fabricated with only a conventional thermal-annealing process. The results of X-ray photoelectron spectroscopy and the maximum density of the surface states (Ns) confirm that the device improvement originates from reduced oxygen-related defects and improved electron trapping due to UV-ozone irradiation.