MgNiO-based metal-semiconductor-metal ultraviolet photodetector

In this study, we report the growth of MgxNi1-xO thin films on quartz substrates by electron beam evaporation. The absorption edge shows a blue shift from 340 nm to 260 nm with increase in the Mg content from 0.2 to 0.8. A metal-semiconductor-metal structured photodetector is fabricated from the Mg0.2Ni0.8O film. At a bias of 5V, the dark current of the photodetector is about 70 nA. The maximum responsivity is about 147.3 mu AW(-1) at 320 nm. In addition, the ultraviolet (UV) (320 nm) to visible (400 nm) rejection ratio is nearly two orders of magnitude. Based on these results, it is proposed that MgxNi1-xO is a potential candidate for application in UV photodetectors.