ZnGa2O4 deep-ultraviolet photodetector based on Si substrate

Abstract Deep-ultraviolet photodetectors with fast response speed are urgently required in flame detection and atmospheric monitoring. A method for reducing oxygen vacancies in ZnGa2O4 films by high-temperature and oxygen thermodynamic conditions is proposed, to increase the response speed of ZnGa2O4/Si heterojunction deep-ultraviolet photodetectors. Here, a ZnGa2O4/Si heterojunction deep-ultraviolet photodetector with excellent performance is fabricated, exhibiting a decay time of ∼67 ms, a dark current of 0.027 nA and a photo-to-dark current ratio of ∼490. These results indicate that the high-temperature and oxygen-rich annealing method proposed here can provide a reference for the fabrication of ZnGa2O4 deep-ultraviolet photodetectors with excellent performance.