Oxide Thin-Film Transistors With IMO and IGZO Stacked Active Layers for UV Detection

Thin film transistors (TFTs) with amorphous InMgO (a-IMO) and InGaZnO (a-IGZO) stacked active layers are proposed to implement high-performance ultraviolet (UV) detectors. In this structure, the IGZO layer serves as the conductive layer and the IMO layer acts as the light absorption layer. The fabricated a-IGZO/a-IMO TFT shows comparable electrical characteristics to those of the conventional a-IGZO TFT as well as high UV photocurrent gain with good visible-blindness. In addition, the a-IGZO/aIMO TFT-based sensor operates with stable and successive light detection. Thus, the a-IGZO/a-IMO TFT has been demonstrated to be able to act as both sensing and switching devices in the pixels of UV image sensors.