Thin-film transistors (TFTs) utilizing titanium-oxide channel layers were fabricated by using a sol-gel process. The device characteristics of the channel layer for the TFTs were enhanced, resulting in a shift of the threshold voltage and in a decrease of the off-current. The on/off current ratio of the ultraviolet-ozone-treated TFTs was as large as 4.78 x 10(5). The surface carrier concentration of the titanium-oxide was decreased due to the decrease in the oxygen deficiency resulting from the negatively-charged oxygen. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.016207jes] All rights reserved.