Phys. Chem. Chem. Phys., 2020,22, 9513-9517. https://doi.org/10.1039/D0CP00586J

Anionic substitution is attracting research interest as a property modulation strategy. Although the effect of nitrogen incorporation on luminescence tuning has been widely reported, the correlation between dodecahedral expansion on Si⁴⁺–N³⁻ co-substitution and crystal-field splitting of Ce³⁺ in garnets is rarely discussed. This work is devoted to unraveling the structure–property relationship between anionic substitution and spectroscopy tuning. Ligand movement patterns of a dodecahedron and an octahedron are investigated for tetragonal distortion and inter-facial distance, both of which indicate an energy level shift originating from the crystal-field effect. The quantitative crystal-field calculation is performed on the basis of ligand coordinates to derive the analytical expression for further confirmation. This work complements the substitution effects of both cationic and anionic chemical species on spectral tuning in garnets, and will be helpful in material design and property modulation of garnet-based luminescent materials.