An approach to achieve the transparent thin film transistors (TTFTs) using transparent electrodes such as ITO or FTO for gate, source and drain electrodes (Free-silicon gate electrode). On the other hand, the high-k transparent metal oxides can be used for this purpose in gate dielectric by a low temperature sol-gel technique. Furthermore, not only use of high-k organic materials in gate dielectric reduces the leakage current but also it improves the device flexibility. The organic-inorganic hybrid composites of SiO2/TiO2-PVP (STP) with different TiO2 ratios are deposited on PET-ITO substrates (Free-silicon gate electrode) as gate dielectric. The thermal behavior and structural characterization of STP films are done by TGA, XRD and XPS analyses. The AFM analyze of STP films shows that they have very smooth surface. A transparent thin layer of ZnO is used as a transistor channel by sputtering technique. Evaluation on electrical performance of OFETs exhibits that they have high mobility, low threshold voltage and acceptable I-on/I-off ratio.