Light Effects on the Bias Stability of Transparent ZnO Thin Film Transistors

We report on the bias stability characteristics of transparent ZnO thin film transistors (TFTs) under visible light illumination. The transfer curve shows virtually no change under positive gate bias stress with light illumination, while it shows dramatic negative shy under negative gate bias stress. The major mechanism of the bias stability under visible illumination of our ZnO The is thought to be the charge trapping of photo-generated holes at the gate insulator and/or insulator/channel interface.