Ultraviolet Photodetector Based on a MgZnO Film Grown by Radio-Frequency Magnetron Sputtering

The metal-semiconductor-metal ultraviolet (UV) photodetector was fabricated on the Mg(0.47)Zn(0.53)O layer grown by radio-frequency magnetron cosputtering. The photodetector shows the peak response at 290 nm with a cutoff wavelength at 312 nm. It exhibits a very low dark current of about 3 pA at 5 V bias, and the UV-visible rejection ratio (R = 290 nm/R = 400 nm) is more than 4 orders of magnitude. The transient response for the detector was measured, and it was found that the rise time is 10 ns and the fall time is 30 ns. The reason for the short response time is related to the Schottky structure.