The Structural and Photoelectrical Properties of Gallium Oxide Thin Film Grown by Radio Frequency Magnetron Sputtering

Gallium oxide thin films were deposited by radio frequency magnetron sputtering technique. Structural, optical and photoelectrical properties of Ga2O3 thin films were investigated in detail. The as-grown Ga2O3 thin films were amorphous, while those annealed film were polycrystalline with monoclinic structure. Amorphous and polycrystalline gallium oxide metal-semiconductor-metal photodetectors were fabricated. However, annealed polycrystalline films have no photoresponse for deep ultraviolet light. The responsivity of the photodetector based on as-grown amorphous film is 122.7 μA/W at 256 nm and the ultraviolet (UV)-to-visible rejection ratios were 100, which indicates that the amorphous Ga2O3 thin films have potential application for solar-blind photodetector. High concentration of oxygen vacancies of amorphous film are considered to be responsible for photoresponse in amorphous gallium oxide thin films.