A self-powered UV photodetector based on the hydrovoltaic and photoelectric coupling properties of ZnO nanowire arrays

We report a novel self-powered ultraviolet (UV) photodetector as sensor node in the internet of things (IoT). The working mechanism of the device relies on the coupling of hydrovoltaic and photoelectric effect of ZnO nanowire arrays. The photodetector can long-term work without any external batteries or power supply units, and the natural water (such as rain, river water and etc) can be used as the fuel to powering the system. Water flow and evaporation on the aligned ZnO nanowire arrays can generate power, and the outputting current is dependent on the UV illumination as photodetecting signal. The UV photodetector has rapid response/recovery processes, and the outputting current increases from 0.112 to 1.899 mu A under UV illumination (365 nm, 20 mW cm(-2)). The UV photodetector as sensor nodes can be integrated with wireless transmitters, constructing self-powered smog monitoring systems in IoT. The self-powered photodetecting signal can reflect the smog degree, and the wireless transmitter can send the smog information to the mobile equipment or cloud. The present results can stimulate a new research trend on the next generation of photodetectors and promote the development of environment monitoring technique in IoT. (C) 2021 Elsevier B.V. All rights reserved.