In this study, amorphous indium gallium zinc oxide (IGZO) thin films with thickness ranges from 13 to 160 nm were deposited on glass. The energy gap of the IGZO measured through transmission spectroscopy was approximately 3.45 eV. When irradiated by ultraviolet (UV) light the transition efficiency (Delta I/I-dark) of the 115-nm-thick IGZO films were found approximately as 23,924. The IGZO thin films were also tested for use as gas sensors. When attached by ozone molecules, the resistance of the film altered as a result of electron transfer from the film to the gas molecules. The fabricated IGZO films can detect ozone to the ppb level. Our results showed that IGZO thin films were capable of sensing both ozone gas and UV light with high sensitivity. (C) 2016 Elsevier B.V. All rights reserved.