| Summary: | 碩士 === 國立交通大學 === 光電工程研究所 === 105 === The highly transparent characteristic of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) makes it possible for the application of the transparent electronics. However, the electrical instability induced by light illumination and gate bias stress is an important issue to be solved in the application. In this study, the short-term response in the drain current (ID) of a-IGZO TFTs under positive bias illumination stress (PBIS) is measured with respect to time in less than 5 seconds under light pulses with altering frequencies and duty ratios. The curves of ID under the light pulses are affected by the different defect reaction rates under light illumination and in the dark. By taking the derivative of the ID-t curves, the defects with different reaction rates can be extracted, and the different behaviors between the excited and recovering parts become clear. Further, a fitting formula is proposed to analyze the defect behaviors, while the fitting parameters τ represent defect of different reaction rates. Besides, the correlation between the parameters τ and the stress time implies the spread of defects. The original behavior of ID in response to light pulses can be fairly reconstructed by the integrating the differential values from the fitting formula with a correction factor of charge trapping. This study substantially proves the mechanism in the time response to light illumination and provides a new method to analyze the defect behaviors, which can be a helpful reference in the development of transparent products using a-IGZO TFTs.
|
|---|
