360° detection of linear ZnO@CFs photoelectrochemical-type ultraviolet photodetector

Applications of omnidirectional ultraviolet (UV) detectors are numerous and promising. There is an increasing demand for flexible UV detectors toward the realization of intelligent and weavable systems. Carbon fibers (CFs) are used in flexible omnidirectional UV detectors due to their linear structure and unique flexibility. In this work, a flexible photoanode for omnidirectional photoelectrochemical (PEC)-type UV photodetectors (PDs) based on wurtzite hexagonal-phase ZnO nanowires grown on CFs is developed. The PD based on ZnO@CFs has a good response for rotation angles in the range from 0° to 360°. After being bent and twisted several hundred times, the PD still exhibits a stable switching period. Furthermore, the detector shows stable photocurrents up to 185 μA cm−2, reproducible switching periods, fast rising and falling response times of 0.17 and 0.12 s, respectively, and excellent spectral selectivity of 300–400 nm. The proposed flexible photoanode has potential applications in wearable PEC UV detectors with 360° detection.