【International Papers】Hybrid Density Functional Theory Study on the Formation Energies of Donor and Acceptor N Impurities in β-Ga₂O₃

      Researchers from the Institute of Plasma Physics and Laser Microfusion have published a dissertation titled " Hybrid Density Functional Theory Study on the Formation Energies of Donor and Acceptor N Impurities in β-Ga₂O₃" in physica status solidi (b).

Abstract

      Hybrid-density-functional-theory calculations are used to evaluate the structural and electronic properties and formation energies of N-doped β-Ga₂O₃. Altogether, eleven interstitial (N_i) and three substitutional (N_OI,II,III) impurity positions are investigated. Since direct evidence of N₂ formation following the annealing of Ga₂O₃ and ZnO matrixes is revealed experimentally earlier, four complexes comprising two N atoms are also considered. It is determined that substitutional nitrogen defects act as deep acceptors, whereas the interstitial defects and N₂-like complexes act as deep donors. Under Ga-rich growth conditions, substitutional nitrogen defects exhibit lower formation energies, with N_OII defects being the most favorable. Under Ga-poor conditions, interstitial defects are more energetically desirable for a wide Fermi energy range, with N_i9 defect being the most favorable. The formation of the N₂-like considered here at solely interstitial positions is energetically very expensive regardless of growth conditions. Finally, the N_i9–N_OI complex is the most desirable one under Ga-rich conditions. This knowledge can serve as a basis for the development of optimal doping strategies, potentially leading to improved performance in future β-Ga₂O₃-based electronic devices.