Insights into Cation-disorder effect on stability, electronic structure and defect properties of Zn-IV-nitrides: The case of ZnGeN2

Abstract

Structural, electronic and intrinsic defect properties of ZnGeN 2 in different space groups are systematically studied using first-principles calculations. Accessibility of cation-disordered structure is verified by formation enthalpy calculations and the rather low formation energies of cation antisite defects. Furthermore, the electronic structures and intrinsic defect properties of ZnGeN 2 semiconductors in all the space groups can be well regulated by cation-disorder. The band gap of ZnGeN 2 can be significantly reduced by cation-disordering. Cation-disordering is revealed to weaken Zn 3 d -N 2 p antibonding at the valence band maximum and enhance the bonding at the conduction band minimum. Electronic structures, as well as associated physical properties, are intimately related to the chemical environment of N atoms. The nonstoichiometrically coordinated N atoms produced by cation disordering show significant influence on the stability and electronic structure of ZnGeN 2 . Our predictive results may inspire further experimental and theoretical exploration on the potential applications of ZnGeN 2 in optoelectronics. • Accessibility of cation-disordered ZnGeN 2 is confirmed by formation enthalpy and defect formation energy calculations. • Zn-IV-N 2 exhibit good modulation in their electronic structures and intrinsic defect properties by cation-disorder. • Cation-disordering is revealed to weaken Zn 3 d -N 2 p antibonding at the valence band maximum and enhance the bonding at the conduction band minimum. • The electronic structures as well as associated physical properties are intimately related to the chemical environment of N atoms.