“…Over the past decades, ultraviolet (UV) sensing technology has triggered enormous interest because of its wide applications in crime investigation, oil spill detecting, fire monitoring, and electrical power line inspection. − Moreover, flexible UV image sensors can be applied in much wider range applications because of their attractive features of being flexible, portable, and wearable. − However, due to the low signal intensity of UV radiation in many practical applications, high-performance flexible UV photodetectors are critical to realize flexible UV imaging . So far, various wide-band-gap semiconductor materials have been explored to fabricate UV photodetectors, such as III-nitrides, − II–VI compounds, − III–VI compounds, , and IV–VI compounds. , Among these wide-band-gap semiconductor materials, metal oxides have been extensively investigated because of their abundant reserves, excellent stability, and environmentally benign nature .…”