Epitaxial growth and solar-blind photoelectric properties of corundum-structured α -Ga 2 O 3 thin films

Abstract Corundum-structured α -Ga 2 O 3 thin films have been employed to deposit on m-plane (300) α -Al 2 O 3 substrates under different temperature, oxygen pressure, pulse laser energy and frequency by laser molecular beam epitaxy method. (300)-oriented α -Ga 2 O 3 epitaxial thin film can be obtained under the appropriate growth parameters. The prepared α -Ga 2 O 3 thin film shows a band gap of 5.15 eV which is larger than that of β- Ga 2 O 3 , exhibiting an excellent solar-blind ultraviolet (UV) characteristic. The α- Ga 2 O 3 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 -Ga 2 O 3 thin film is a promising candidate for use in solar-blind photodetectors.