High-Responsivity Solar-Blind Photodetector Based on Mg0.46Zn0.54O Thin Film

Adopting relatively high substrate temperature and low growth rate, single-phase wurtzite Mg0.46Zn0.54O film is grown on a quartz substrate by homemade magnetron sputtering. Solar-blind photodetector is fabricated based on the MgZnO film and shows a peak responsivity of 3.4 A/W at 265 nm with a cutoff wavelength of 280 nm under 10 V. As applied voltage increased to 70 V, the peak responsivity is up to 31.1 A/W corresponding to an internal gain of 148 times. The large internal gain was attributed to the trapping of photoionized holes atEv+ 282 meV deep level through deep-level transient spectral measurement.