First-Principles study for the influence of ion vacancies on the doped Cr3+ and transition dipole moment in anti-perovskite structure La3(SiN2O2)N

Typically, the luminescence properties of doped luminescent centers, such as rare earth ions or transition metal ions, are significantly influenced by the properties of the luminescent host materials. In this study, we focus on how the electronic band structure and transitions between the valence band maximum (VBM) and conduction band minimum (CBM) are affected by the formation of individual V_La or V_Si, as well as the coexistence of V_La with V_Si in La₃(SiN₂O₂)N. The doped Cr³⁺ as luminescent centers preferentially substitutes for Si⁴⁺ rather than La³⁺.The band gap characteristics of La₃(SiN₂O₂)N, associated with its absorption properties, can be modified by the presence of ion vacancies and doped Cr³⁺. Additionally, the computed transition dipole moment of La₃(SiN₂O₂)N: V_Si, Cr³⁺ is the highest. This indicates the maximal transition between VBM and CBM, resulting in the most robust charge transfer from the p orbital of N³⁻ to the d orbital of Cr³⁺.Enhanced charge transfer can also result in effective luminescence. Therefore, it can be concluded that La₃(SiN₂O₂)N with individual V_Si is suitable as a luminescent host material for Cr³⁺ doping. The study of La₃(SiN₂O₂)N with different ion vacancies and Cr³⁺ doping provides information for the development of new luminescent materials that exhibit strong luminescence.