ИСТИНА

The defect physics in ternary ZnGeN2 may be expected to be more complex than in binary nitrides. In a previous study we found that among the native defects, antisites ZnGe and GeZn have low energy of formation, and predict the material to be intrinsically slightly p-type. This opens questions about what is the origin of the usually found n-type doping and how to effectively p-type dope the material. In this study, we examine interstitial defects and consider some candidates for p-type doping using the FP-LMTO supercell approach along with LDA+U corrections of the gap. We find that the interstitials have higher energy of formation but present nonetheless interesting physics. While Zni is a shallow donor with a Zn-s like resonance in the conduction band, Gei has a deep Ge-s level in the gap. Ni prefers a split interstitial configuration with states related to the N2 molecule. As far as p-type dopant candidates, we consider Ga, which however suffers from antisite compensation between GaGe acceptor and GaZn donor behavior. Cu prefers the Zn over the Ge or interstitial sites but is nonetheless a deep acceptor. C prefers the N site over Ge or Zn sites but again provides a rather deep level at about 0.7 eV above the VBM.