Self-powered UV photodetectors based on ZnO nanomaterials

Self-powered photodetectors can work with low power consumption or even without any supply from external power sources, and they are recognized as one of the developing trends of next-generation optoelectronic devices. As one of the most-known n-type metal oxides applied in electronic devices, ZnO nanostructures and their heterostructures with other appropriate materials have been widely applied in the assembly of self-powered UV photodetectors. In this review, the recent research on different types of ZnO-based self-powered UV photodetectors is outlined. ZnO nanostructures with different dimensionalities adopted in these photodetectors are discussed in detail. The influences of specific effects, such as the piezo-phototronic effect, the pyro-phototronic effect, the photo-gating effect, and even their fusions, on modulating the self-powered photo-response of these photodetectors have also been demonstrated. The applications of these photodetectors in UV sensing, environmental recognition, wearable devices, functional devices, and light communication are displayed. Finally, possible opportunities and directions for the future developments of these photodetectors are proposed.