Article history: Received 11 October 2013 Received in revised form 20 January 2014 Accepted 21 January 2014 Available online 11 February 2014 This paper presents a method to deposit titanium oxide (TiOx) films from a sol containing IV titanium isopropoxide Ti[OCH(CH3)2]4, 2-methoxyethanol, CH3OCH2CH2OH and ethanolamine H2NCH2CH2OH, in order to obtain layers with thickness above 220 nm with the required characteristics to be used in Metal–Insulator–Semiconductor, MIS, structures and polymeric thin film transistors, PTFTs. The effect of using different component ratios is described. The dielectric constant was in the order of 12, the critical electric field was 5 10 V/cm and the density of states at the interface was less than 1 10 cm . The analysis of MIS structures prepared with these TiOx layers shows that they are suitable for using in PTFTs. The fabrication of independent bottom gate PTFTs with poly(3-hexylthiophene), P3HT, on top of the TiOx layer is described, obtaining a major reduction in the operation voltage range from 30 V to 4 V, while maintaining the typical mobility for P3HT PTFTs. 2014 Elsevier Ltd. All rights reserved.