Novel BeZnO Based Self-Powered Dual-Color UV Photodetector Realized via a One-Step Fabrication Method

摘要

In this work, we fabricated a novel BeZnO based dual-color UV photodetector through a one-step electron beam evaporation of asymmetric Ti/Au pair. A dual-phase BeZnO alloy film with dual bandgap of similar to 3.5 eV (similar to 355 nm) and similar to 4.6 eV(similar to 270 nm) was artfully utilized as active layer to realize dual-color response. This photodetector shows a noticeable photovoltaic characteristic and can be utilized as an excellent self-powered device. The device exhibits two cut-off response wavelengths at similar to 275 nm and similar to 360 nm under zero bias, which are corresponding to UVA and UVC region, respectively. According to the dynamic response spectra under UV radiation, the device presents excellent stability and reproducibility without external power supply. In addition, the device has an ultrafast response speed, with a rise time of similar to 35 mu s and a decay time of similar to 880 mu s. Finally, a physical model based on energy band theory is proposed to demonstrate that the self-powered behavior is attributed to the asymmetric Schottky barrier heights caused by the hole-trapping process occurred in electrode/BeZnO interface. To the best of our knowledge, this is the first report on BeZnO based self-powered UV photodetector. Our findings demonstrate a novel and facile route to realize high performance self-powered UV photodetectors for multipurposes.