Drain current response to fast illumination pulse for amorphous In-Ga-Zn-O thin-film transistors

In this paper, the characteristic of the amorphous indium-gallium-zinc-oxide thin-film transistors under steady bias and fast multiple-pulse illumination stress is analyzed. The change in the drain current ( Δ I _D ) with respect to time is measured under different light intensities and pulse frequencies. The mechanism is proposed to explain the results by correlating the oxygen vacancy ( V _O ) reacting with the light-induced electron-hole (e-h) pairs. The results can be well analyzed by the fitting formula and parameters for the different light pulse frequencies. The tendency proves that not all the V _O react with e-h pairs at the same reaction rate. It is observed for the first time the number of V _O with fast reaction decreases with the pulse frequency. A model is proposed to describe the relation between the number and reaction rate of V _O .