Thorough Elimination of Persistent Photoconduction in Amorphous InZnO Thin-Film Transistor via Dual-Gate Pulses

Amorphous InZnO (a-IZO) thin film transistors (TFT) are highly sensitive to green or shorter wavelength light, and can be applied as photosensors. Nonetheless, the application of a-IZO TFT as photosensor is hindered by its persistent photoconduction (PPC), which leads to severe threshold voltage shift and low response speed. Here, we show that the PPC in the a-IZO TFT cannot be thoroughly eliminated by single-gate positive pulses. The residual ionized oxygen vacancy (Vo(2+)) per gate pulse would gradually accumulate over time, giving rise to an increment of PPC under long-term illumination. To tackle this issue, a dual-gate transistor architecture together with dual-gate pulses configuration is proposed. Due to a stronger gate controllability, the residual Vo(2+) that lie in the middle of the IZO channel is reduced, and the PPC of a-IZO TFT is thoroughly eliminated.

Automated summary

Amorphous InZnO (a-IZO) thin film transistors (TFT) exhibit high sensitivity to green or shorter wavelength light and can be used as photosensors. However, the persistent photoconduction (PPC) phenomenon in a-IZO TFT limits its application as a photosensor, resulting in severe threshold voltage shift and low response speed. By employing a dual-gate transistor architecture and dual-gate pulses configuration, the PPC of a-IZO TFT is completely eliminated.