The effect of metal-rich growth conditions on the microstructure of ScxGa1-xN films grown using molecular beam epitaxy

Epitaxial ScxGa1-xN films with 0 ≤ x ≤ 0.50 were grown using molecular beam epitaxy under metal-rich conditions. The ScxGa1-xN growth rate increased with increasing Sc flux despite the use of metal-rich growth conditions, which is attributed to the catalytic decomposition of N2 induced by the presence of Sc. Microstructural analysis showed that phase-pure wurtzite ScxGa1-xN was achieved up to x = 0.26, which is significantly higher than that previously reported for nitrogen-rich conditions, indicating that the use of metal-rich conditions can help to stabilise wurtzite phase ScxGa1-xN.