In this study, ITO-coated PET was used as the substrate to create a flexible and transparent structure. a-IGZO (amorphous InGaZnO4) is preferred for the semiconductor layer in order to keep the related TFT device stable at high performance for a long term. In addition, as an innovative method to increase the electrical performance of this TFT, the HfO2 dielectric layer surface has been modified with SrTiO3. All layers of the relevant flexible transparent thin-film transistor (TTFT) structure were produced by the sputtering method. In this work, fabricated TFT devices were evaluated in terms of the structural, morphological, chemical, and optical properties using X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray photoelectron (XPS), and UV-Vis spectroscopy, respectively. In addition, in order to examine the long-term electrical performance of the related TFT devices, the relevant products were put into the reliability test and their electrical performances before and after the tests were determined. The average optical transmittance values of the developed TFT devices in the wavelength range of 300-700 nm were determined as 79.80%. Before the reliability tests, the maximum fet mobility value was determined as 26.82cm(2)/Vs. After the reliability tests, it was seen that this value decreased to only 26.27cm(2)/Vs. The fact that the fet mobility value is so high after long-term stability tests shows that the relevant flexible and transparent TFT device can be used to drive LC (liquid crystal) and OLED (organic light emitting diode) subpixels in LCD and OLED screen technologies.