High-performance flexible deep ultraviolet photodetector based on crossed microwires heterojunction for real-time target trajectory tracking system

Deep ultraviolet photodetectors have enormous potential applications in guidance systems, fire detection, and pilotless automobiles. Ga₂O₃ materials with ultra-wide optical bandgap are powerful candidates for deep ultraviolet detection. Herein, a high-performance crossed Ga₂O₃/CsCu₂I₃ microwires heterojunction flexible photodetector was successfully prepared using a simple mechanical transfer method. The photodetectors exhibit excellent optoelectrical properties towards solar-blind light, with a high responsivity of 178.9 A/W, a large specific detectivity of 1.1 × 10¹¹ Jones, a great photo-to-dark current ratio of 5.4 × 10⁴, and an ultra-fast response/decay time of 19 μs/0.4 ms under −1 V bias. Especially, due to formation of the built-in electric field, the photodetector can operate normally at zero bias with a responsivity of 5.9 mA/W. Thanks to the excellent mechanical stability of 1D micro-nanostructure materials, the photodetectors show a negligible decrease in photoresponse after 600 bending cycles. In addition, a light-tracking system was prepared using the photodetectors, which can track the movement of light source and display azimuth of the light spot in real-time on the user interface under ambient light. Our work provides a promising route for high-performance flexible deep ultraviolet photodetectors, and facilitates their application in intelligent tracking and positioning.