Sputtering Growth of Nitrogen-doped Ga2O3 Films and Applications of Photodetectors

Thin-film Ga 2 O 3 -based solar-and visible-blind photodetectors (PDs) stand at the forefront of future applications, with their performance closely tied to film quality.Employing radio frequency magnetron sputtering, we deposited an intrinsic Ga 2 O 3 thin film onto a double-throw (0001) sapphire substrate at a substrate temperature of 500 ℃ for 10 min.Subsequently, using the intrinsic Ga 2 O 3 thin film as the substrate and maintaining constant process parameters, including background vacuum, working pressure, growth temperature, sputtering power, and duration, we introduced N 2 at various flow rates (0, 5, 10, 15, 20, and 25 sccm) for the reactive sputtering growth of nitrogen-doped amorphous Ga 2 O 3 thin films.Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV-Vis spectrophotometry, and Hall effect measurements were utilized to probe the impact of N 2 flow rate on the growth rate, surface morphology, elemental composition, crystallization quality, and optical characteristics, and electrical properties of the Ga 2 O 3 thin films.With increasing N 2 flow rate, the films exhibited a notable redshift of the absorption edge, accompanied by a decrease in optical band gap.Hall effect measurements confirmed the stable p-type conductivity of the nitrogen-doped Ga 2 O 3 thin films.Subsequently, metal-semiconductor-metal-type PDs were fabricated using the nitrogendoped Ga 2 O 3 thin films.These PDs demonstrated heightened sensitivity to 365 nm near-UV light, boasting a remarkable response of 1.32 × 10 2 A/W and a high response speed of 0.028/0.17s.