【Others Papers】Electronic structure and defect chemistry of N-doped κ-Ga₂O₃: challenges toward P-type doping

      Researchers from the Jiaying University and Sun Yat-Sen University have published a dissertation titled "Electronic structure and defect chemistry of N-doped κ-Ga₂O₃: challenges toward P-type doping" in Electronic Structure.

Abstract

      Ga₂O₃ has garnered substantial interest owing to its promising applications in power electronics and optoelectronics. Herein, the electronic properties of N-doped κ-Ga₂O₃ are explored through density functional theory calculations. A variety of N-doped complex defects are examined, including N_O (N-doped κ-Ga₂O₃), N_OV_O (N-doped κ-Ga₂O₃ with O vacancy), N_OV_Ga (N-doped κ-Ga₂O₃ with Ga vacancy), N_OO_i (N-doped κ-Ga₂O₃ with O interstitial), N_OGa_i (N-doped κ-Ga₂O₃ with Ga interstitial), alongside nitrogen substituting gallium at tetrahedral (N_Ga,tetra) and octahedral (N_Ga,octa) sites. Analysis of their formation energies reveals that N_O predominates under both Ga-rich and O-rich environments, functioning as a shallow acceptor. Intriguingly, under Ga-rich conditions, there exists a pronounced preference for N_OV_O defects over other acceptor-like deep defects, implying that such complexes may obstruct the attainment of p-type conductivity in κ-Ga₂O₃ due to extensive compensation by oxygen vacancies. Moreover, it is demonstrated that N_OV_O complexes can elicit red luminescence, arising from oxygen vacancies coupled with holes localized at acceptor sites introduced by N doping. The intricate electronic structure of κ-Ga₂O₃ with these complex defects is elucidated through comprehensive analyses of the density of states and electronic band structures. Complementary examinations of electron localization and real-space wavefunctions further illuminate the influence of these defects on the κ-Ga₂O₃ lattice. Notably, N-doped κ-Ga₂O₃ exhibits enhanced anion diffusion and charge delocalization, suggesting that nitrogen doping can substantially improve hole mobility and electrical conductivity. This study offers valuable theoretical insights into the limitations and prospects of nitrogen doping as a method for achieving p-type conductivity in κ-Ga₂O₃.

DOI：

https://doi.org/10.1088/2516-1075/ae4701