•연구자: 물리학과 위상원, 이윤상
•발표일: 2026.06
•DOI: https://doi.org/10.1016/j.mtchem.2026.103702
•Yu June Kim et al., Materials Today Chemistry (Q1), Volume 54, 103702 (2026)
•Abstract
Transition-metal-doped phosphors have emerged as sustainable alternatives to rare-earth ion-based phosphors. These materials address concerns related to resource criticality and cost while providing versatile optical tunability. The flexible cation distribution in inverse-spinel oxides enables selective stabilization of oxidation states of transition metal ions. Herein, we report Mn-doped Zn2Sn1-xTixO4 (0 ≤ x ≤ 1) as a model system for demonstrating valence-state engineering through B-site substitution. Structural analyses confirmed a continuous inverse-spinel solid solution accompanied by monotonic lattice contraction. Rietveld refinement further revealed systematic decreases in the cation‒oxygen bond lengths. Interestingly, the Mn–O bond length in tetrahedral and octahedral complexes exhibit opposing trends, exhibiting progressive destabilization of Mn2+ in the tetrahedral sites but enhanced stabilization of Mn4+ in octahedral coordination as x increased. The photoluminescence spectra revealed a distinct color evolution from green (Mn2+) to red emission (Mn4+), demonstrating effective compositional control over the emission color. These results validate valence-state engineering for developing next-generation, color-tunable phosphors.