Structural and optical properties of β-Ga2O3 films deposited on MgAl2O4 (1 0 0) substrates by metal–organic chemical vapor deposition

β-Ga2O3 films have been prepared on MgAl2O4 (1 0 0) substrates at different temperatures (550–700 °C) by metal–organic chemical vapor deposition (MOCVD). Microstructure analysis revealed that the sample deposited at 650 °C was the single crystal epitaxial film with the best crystallinities. The epitaxial relationship was β-Ga2O3 (1 0 0) || MgAl2O4 (1 0 0) with β-Ga2O3 [0 0 1] || MgAl2O4 〈0 1 1〉. A schematic diagram was proposed to explain the domain structure in the film layer. The average transmittance for the films in the visible range was over 90%. An ultraviolet (UV)–green photoluminescence (PL) from about 350–600 nm was observed at room temperature (RT). The corresponding PL mechanisms were investigated. -- Highlights: • β-Ga2O3 films have been prepared on MgAl2O4 (1 0 0) substrates by MOCVD. • The growth mechanism of the four-fold rotation domain structure was explained. • The average transmittance of the films in the visible wavelength range exceeded 90%. • The PL spectrum revealed an UV-Green emission from 350–600 nm