Effect of ozone gas exposure on drain current of solution-processed IGZO-TFT

Abstract The drain current ( I D ) of indium gallium zinc oxide thin-film transistors (IGZO-TFTs), fabricated by spin coating, decreases even when they are exposed to ozone gas at a concentration equal to or lower than 5 ppm. The I D reduction rate increases when the film thickness and the firing temperature in the spin-coating process of IGZO layer decreases. In these samples, the peak intensity ratio of the O 1s X-ray photoelectron spectroscopy (XPS) peak due to the OH group and the intensity of the infrared (IR) absorption band at 3000 cm −1 –3500 cm −1 due to the OH stretching vibration increase. This indicates that OH groups within the IGZO film contribute to the ozone reaction mechanism. These findings are significant for developing high-sensitivity ozone sensors using a simpler process.