A wire-shaped and high-sensitivity photoelectrochemical ultraviolet photodetector based on TiO₂ nanotube arrays

The multifunctional and smart ultraviolet photodetectors are of great significance and necessity for applications in many fields, especially in health and environmental risk monitoring. Hence, a wire-shaped photoelectrochemical type ultraviolet photodetector based on photoanode of TiO2 nanotube arrays (TNAs) fabricated by electrochemical anodization is demonstrated in this work. The TNAs can provide direct pathways for carriers and large internal surface area. The assembled UV detector presented a high photocurrent density of 110 μA cm−2, a high ON/OFF ratio of 467, and a fast rise and decay response time of 13 and 19 ms for the optimal thickness of the photoanode of TNAs. Moreover, the detectors also exhibited visible-blind characteristics and an excellent linear response even under weak irradiation (20–100 μW cm−2). The results are beneficial to realizing omnidirectional and wearable optoelectronic devices.