Growth and characterization of MgGa₂O₄ films on silicon substrates

Abstract We have investigated the deposition of MgGa 2 O 4 films on silicon substrates by pulsed laser deposition under varying substrate temperatures and oxygen pressures. The effects of these growth parameters on film composition, crystallinity, growth rate, optical properties, and photoluminescence behavior were systematically studied. X-ray diffraction analysis revealed that films deposited at 500 °C and 0.1 Pa exhibited the highest crystallinity with a (111) preferred orientation, whereas those grown at lower temperatures or higher pressures tended to be amorphous or poorly crystalline. Clear Fabry–Perot interference fringes were observed in the optical reflectance spectra, allowing the optical bandgap to be estimated at approximately 5.5 eV for films grown at 500 °C. Photoluminescence measurements revealed broad visible emissions attributed to defect states, along with a distinct UV emission peak at ∼346 nm in films deposited at elevated temperatures. These results demonstrate the critical role of substrate temperature and oxygen pressure on the structural and optical properties of MgGa 2 O 4 films, emphasizing their potential as promising materials for advanced electronic and optoelectronic applications compatible with silicon-based integrated circuits.