Photoluminescence from GaN Implanted with Be and F

GaN samples are implanted with Be and F and annealed in different conditions to activate the Be-Ga acceptors. Photoluminescence spectra are studied to recognize the defects. The UVLBe band with a maximum at 3.38 eV and the YLBe band with a maximum at 2.15 eV are observed and associated with Be. The sequential implantation of Be and F ions into GaN at 600 degrees C reduces the concentration of nitrogen vacancies (V-N), as evidenced by the lack of the green luminescence band associated with the isolated nitrogen vacancy. First-principles calculations are employed to find parameters of defects that can form after implantation.