Performance improvement of a ZnMgO ultraviolet detector by chemical treatment with hydrogen peroxide

Abstract

Herein, ZnMgO thin film ultraviolet (UV) photodetectors based on metal–semiconductor–metal structure were fabricated on a-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The effect of H₂O₂ solution treatment on the properties of the ZnMgO thin film and its UV photodetectors was investigated. After immersing the ZnMgO UV photodetector in a H₂O₂ solution at 100 °C for 3 min, the dark current of the device was reduced by more than one order of magnitude under 1 V bias, whereas the responsivity was slightly decreased. More interestingly, the response speed became much quicker and insensitive to the atmosphere after the treatment of the photodetector with H₂O₂ solution, which can be attributed to the reduction in the oxygen vacancy defects. Our findings may provide a promising approach for improving the performance of photodetectors.