Self‐Powered MXene/a‐Ga 2 O 3 Schottky Solar‐Blind UV Photodetector for UV Imaging and Optical Communication

ABSTRACT Self‐powered solar‐blind ultraviolet photodetectors have garnered significant attention across environmental, industrial and military domains, owing to their ability to perform power‐independent photodetection with high environmental sensitivity. Here, we report an advanced self‐powered solar‐blind ultraviolet photodetector based on an MXene/a‐Ga 2 O 3 Schottky junction, featuring transparent conductive MXenes as the Schottky electrode. Under zero bias, the photodetector exhibits a responsivity of 53.8 mA/W, as well as a response speed of 24/74 ms under 254 nm illumination. Thanks to the excellent Schottky contact at the MXene/a‐Ga 2 O 3 interface that creates a strong built‐in electric field, the detector operates robustly even under dim illumination of 1 µW/cm 2 . The photodetector also demonstrates an ultraviolet/visible rejection ratio (R 254 nm /R 500 nm = 1563), enabling effective rejection of visible light interference in practical scenarios. Furthermore, we demonstrate its practical utility in image acquisition and ultraviolet communication signal transmission. This work demonstrates the feasibility of combining solution‐processed MXene with a‐Ga 2 O 3 for low‐cost, scalable self‐powered ultraviolet detection systems and related applications.