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MagnesiumIII-V semiconductorsVacanciesLuminescencePhotoluminescenceBand gapFermi levelsDensity functional theoryDissociationOptically detected magnetic resonance
Abstract:
Defects may cause compensation or act as recombination centers in Mg-doped GaN. Using hybrid functional calculations, we investigate the effects of nitrogen vacancies (VN) and Mg-vacancy complexes (MgGa-VN) on the electrical and optical properties of GaN. We find that MgGa-VN are compensating centers in p-type but electrically inactive in n-type GaN. They give rise to a broad emission at 1.8 eV, explaining the red luminescence that is frequently observed in Mg-doped GaN, regardless of the Fermi level. Nitrogen vacancies are also compensating centers in p-type GaN and likely contribute to the yellow luminescence that has been observed in Mg-doped GaN.