Epitaxial growth and solar-blind photoelectric properties of corundum-structured α-Ga2O3 thin films

Corundum-structured α-Ga2O3 thin films have been employed to deposit on m-plane (300) α-Al2O3 substrates under different temperature, oxygen pressure, pulse laser energy and frequency by laser molecular beam epitaxy method. (300)-oriented α-Ga2O3 epitaxial thin film can be obtained under the appropriate growth parameters. The prepared α-Ga2O3 thin film shows a band gap of 5.15 eV which is larger than that of β-Ga2O3, exhibiting an excellent solar-blind ultraviolet (UV) characteristic. The α-Ga2O3 thin film exhibits obvious photoresponse under 254 nm UV light irradiation, and it increases in photocurrent with both the increase of optical input power and applied bias. However, it is not sensitive to 365 nm light. The results suggest that α-Ga2O3 thin film is a promising candidate for use in solar-blind photodetectors.