Reduction of vacancy defects induced by thermal annealing in β-Ga2O3 epilayer

The effects of annealing in oxygen atmosphere of beta-Ga2O3 epilayers were investigated by X-ray photoelectron spectroscopy, photoluminescence and Fourier-transform infrared spectroscopy. The increasing proportions of Ga3+ and O-L (lattice oxygen) signifies the reduction of V-O as the annealing temperature rising. The variations of the photoluminescence emissions demonstrate the improvement of the crystal quality and reduction of V-O(1), V-O(2) and V-Ga. V-O and V-Ga are filled with oxygen atoms and gallium atoms after annealing, mainly attributed to the bonds con-structions of Ga (1)-O (1) and Ga (1)-O (2) in GaO4 tetrahedra. These results offer detailed in-formation and guidelines for removing intrinsic point defects in beta-Ga2O3.