ZnO-based photodetector: from photon detector to pyro-phototronic effect enhanced detector

As a direct bandgap semiconductor, zinc oxide (ZnO) has attracted substantial attention in the UV detecting field because of its wide bandgap and high exciton-binding energy. Benefiting from its pyroelectrical property, the response range of ZnO-based photodetectors can expand to the visible range and even infrared light by using the light-heating effect. In this review, ZnO-based photodetectors are summarized, from pure pyroelectric detectors and traditional photon detectors based on internal photoelectric effects to the hybridized photodetectors with pyroelectric and photoelectric effects. Also, the pyro-phototronic effect is presented as an efficient way to solve the slow response problem of most ZnO-based photodetectors by naturally coupling the light-self-induced pyroelectric effect and internal photoelectric effect. Lastly, we review the recent achievements of these ZnO-based photodetectors, discuss the challenges and look forward to the future of pyro-phototronic effect enhanced photodetectors.