Mechanism of Hysteresis for a-IGZO TFT Studied by Changing the Gate Voltage Waveform in Measurement

In this paper, we investigate the response time of oxygen vacancies on the hysteresis for the amorphous indium–gallium–zinc oxide thin-film transistors. The fast pulse measurement method is used to observe the drain current under the different sweeping speeds of gate voltage to clarify the mechanism of the hysteresis. Effects of light intensity and temperature are also discussed. Based on the results and the analysis, the model of oxygen vacancies is proposed to explain the effect of sweep speed on the hysteresis, which would be important for the devices to be driven in their circuit application.