P-i-n ZnO/CuO/PEDOT:PSS heterojunction featuring Ag nanowire electrode for application in high-performance wearable self-powered ultraviolet detector

Excessive exposure to ultraviolet (UV) radiation during outdoor activities poses considerable health risks, necessitating quantitative UV monitoring. This has driven the development of wearable, flexible, and self-powered UV photodetectors capable of effective UV detection to trigger protective action. In line therewith, this study proposes a flexible, self-powered UV detector-featuring a p-i-n multilayer film structure comprising ZnO nanorods as the n-layer, PEDOT:PSS as the p-layer, a CuO intercalation layer as the i-layer, and Ag nanowires (AgNWs) as the top electrode-which can be adapted into wearable technology. Under 365-nm UV illumination (intensity of 477 μW·cm - ²), the device demonstrates a responsivity of 0.011 A·W −1 , high light-to-dark current ratio of 2.1 × 10 3 , and response/recovery times of 55–60 and 109–110 ms, respectively, without requiring an external power supply. It also exhibits remarkable mechanical durability, maintaining stable photocurrent output after 100 cyclic switching tests and > 10 3 bending cycles. Furthermore, the recorded photoresponse of the p-i-n ZnO/CuO/PEDOT:PSS/AgNWs is 70–73 times higher than that of the conventional ZnO/PEDOT:PSS bilayer. These results indicate that the proposed detector is highly suitable for real-time outdoor UV monitoring, serving to prevent overexposure and the associated adverse health effects.