Effect of Oxygen Vacancy Ratio on a GaZTO Solar-Blind Photodetector

Abstract

A gallium-zinc-tin-oxide (GaZTO) solar-blind photodetector was fabricated via radio frequency sputtering. The transmittance of the GaZTO thin film was >80% in the visible light region, and its energy bandgap ranged from 4.11 to 4.23 eV. Manipulating the oxygen flows changed the ratio of oxygen vacancies, which was confirmed by X-ray photoelectron spectroscopy. The ratio of oxygen vacancies in the GaZTO thin films impacted the performance of the photodetectors. The photocurrent, responsivity, and ultraviolet–visible rejection ratio of the GaZTO solar-blind photodetector were 1.23 × 10−6 A, 9.12 × 10−2 A/W, and 3.48 × 104, respectively, at a 10 V bias under 280 nm light illumination. The transient responses of the synthesized photodetectors were measured and discussed.