Epitaxial growth of (AlxGa1−x)2O3 thin films on sapphire substrates by plasma assisted pulsed laser deposition

(AlxGa1−x)2O3 was grown on a-plane sapphire substrates at 500 °C by plasma assisted pulsed laser deposition (PLD) in the whole Al concentration range. The films were characterized using x-ray photoelectron spectroscopy (XPS), x-ray diffraction, atomic force microscopy, and spectrophotometry. By using XPS to measure the bandgap of the films, it was found that as the Al concentration x changes from 0.00 to 1.00, the bandgap ranges from 5.3 to 8.5 eV. The results show that plasma assisted PLD is a promising method to grow ultra-wide bandgap (AlxGa1−x)2O3 at low temperatures, which paves the way for the application of power devices and other functional devices based on (AlxGa1−x)2O3.