Hybrid Density Functional Theory Study on the Formation Energies of Donor and Acceptor N Impurities in β‐Ga2O3

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 (Ni) and three substitutional (NOI,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 NOII defects being the most favorable. Under Ga‐poor conditions, interstitial defects are more energetically desirable for a wide Fermi energy range, with Ni9 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 Ni9–NOI 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.