We investigated the hysteresis and off-current (Ioff) of amorphous In-Ga-Zn oxide thin-film transistors illuminated by 400 nm light at various intensities. Both hysteresis and Ioff are induced by the ionized oxygen vacancy (Vo2+) that forms at the interface between the gate insulator and active layer. In our measurements, Ioff was much less than the estimated photocurrent. Ioff showed a rapid nonlinear increase with light intensity, while the photocurrent of a conventional crystalline semiconductor is expected to show a linear relationship. Furthermore, a numerical analysis suggested that the response time of Vo 2+ should be considered when analyzing the hysteresis of these devices.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering