Effect of different partial pressure on Ga-doped ZnO UV photodetectors by RF sputtering

Ga-doped zinc oxide metal-semiconductor-metal ultraviolet photodetectors were fabricated by radio frequency magnetron sputtering on quartz substrates. The films' Ga content were relatively high to enlarge the bandgap and obtain low dark current. In addition, it was found that the devices' performance was significantly improved by proper gas flow ratios of O2/Ar during deposition. The responsivity and UV-to-visible rejection ratio of photodetector were 16.08 A/W and 5.44×10⁵ at 10 V applied bias with 280 nm illumination.