Amorphous gallium zinc oxide (a-IGZO) is a target metal oxide material that has attracted attention recently. It has the advantages of amorphous silicon and polycrystalline silicon on common displays, with high electron mobility, best uniformity, and low cost of the process. When TFT is applied to a large-size and high-resolution display, the switching time allocated to each transistor becomes less, and the research and improvement of the electrical properties of the transistor are more likely to be important. In this study, we explored the feasibility of applying transistor technology to indium gallium zinc oxide thin-film transistors using stacked gate dielectric layers of different high-k materials. The electrical results show that the gate dielectric layer of the Ta₂O₅/HFO₂/Al₂O₃ stacked structure has better characteristics of the transistor than the single-layer gate dielectric layer. The Ta₂O₅/HFO₂/Al₂O₃ stacked structure could increases the driving current by 40%, and improve gate capacitance value, carrier mobility, and Ion/Ioff ratio. Such stacked dielectric structure have different oxygen density among dielectric layers, which will form Diople[14], attract electrons in the channel layer, so that the stacked structure has a larger driving current and mobility compared with the single-layer gate dielectric layer. Based on the study, the stacked structure dielectric layer is currently widely used in semiconductor factories and is fully compatible with the existing integrated circuit process technology, making the stacked gate dielectric layer have the potential to be used in high-performance transistor technology and become the next generation of transistors. Forward-looking technology. In the second part of this research, we conducted indium gallium zinc oxide thin film transistors under different wavelengths of light. After studying the photoreaction, it is found that it has photosensitivity and is obviously dependent on the wavelength of light. It shows that indium gallium zinc oxide thin film transistors are not only used in switching elements, but also in photo-detectors. The application also has potential.