Study on the time response of a-InGaZnO thin film transistor under pulse illumination and positive bias stress
|關鍵字:||脈衝光照及正向偏壓下對非晶氧化銦鎵鋅薄膜電晶體時間響應之研究;Study on the time response of a-InGaZnO thin film transistor under pulsed illumination and bias stress|
The unique feature of high transparencyfor a-IGZO TFTs makes the development of the transparent electronics possible. However, the instability induced by light illumination as well as the gate bias may hinder the practical applications. In this work, the time response of the TFTs under light illumination and bias stress is studied. By measuring the drain current change with time under single light illumination and positive gate bias (PBS), the time response is investigated. We observed that the positive bias stress instability would play a part of the time response for light illumination. The PBS instability is taken as the background and can be deducted separately. Further, we propose the fitting formula of time response for light illumination to describe the behavior which can be explained by the proposed mechanism. The mechanism is correlated to the oxygen vacancy reacting with the light-induced electron-hole pairs. In real situations, the devices in the transparent electronics are rarely illuminated only for once. We therefore further studied the time response to the multiple-pulse illumination and found that it can be fitted by the same formula and parameters. This study substantially proves the model and mechanism of time response to the light illumination. It reveals the possibility to use the proposed fitting formula in the more complicated illumination cases, which can be an important reference for the development of transparent products using a-IGZO TFT.
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