A practicable route to improve the responsivity of Mg0.2Zn0.8O ultraviolet photodetectors

Abstract The paper reports a study of the thermal annealing effects on Mg 0.2 Zn 0.8 O ultraviolet photodetector with sequential annealing temperature (500, 600, 700 and 800 °C). As for the single hexagonal phase photodetector, the responsivity suddenly increases from 600 to 700 °C, which has been interpreted in terms of a qualitative model considering the thermal effects on the surface film. These results reveal a practicable route to improve the responsivity of Mg 0.2 Zn 0.8 O ultraviolet photodetector via the device thermal annealing.