1：Experimental Design and Method Selection:

The phosphors were synthesized via solid-state reaction. X-ray diffraction (XRD) was used for structural analysis, scanning electron microscopy (SEM) for morphology, and fluorescence spectrophotometry for photoluminescence properties. Temperature-dependent measurements and decay curves were performed using specific spectrometers.

2：Sample Selection and Data Sources:

Samples were prepared with varying Eu3+ doping concentrations (x = 0.005 to 0.10) using raw materials including BaCO3, GeO2, TeO2, Eu2O3, and Na2CO

3：005 to 10) using raw materials including BaCO3, GeO2, TeO2, Eu2O3, and Na2COList of Experimental Equipment and Materials:

3. 3. List of Experimental Equipment and Materials: Equipment includes Philips X'Pert MPD XRD, JEOL JSM-6490 SEM, HITACHI F-4600 fluorescence spectrophotometer, Edinburgh FLS 980 spectrometer, and integrating sphere with Xe lamp. Materials are BaCO3 (A.R.), GeO2 (A.R.), TeO2 (A.R.), Eu2O3 (99.99%), Na2CO3 (A.R.), and white BaSO4 reference.

4：99%), Na2CO3 (A.R.), and white BaSO4 reference. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Raw materials were weighed, ground, preheated at 400°C for 2 hours, and reheated at 800°C for 10 hours. XRD measurements were done with Cu Kα radiation, SEM for imaging, and photoluminescence spectra were recorded at room temperature and varying temperatures.

5：Data Analysis Methods:

Data were analyzed using GSAS software for XRD refinement, Judd-Ofelt theory for symmetry analysis, Arrhenius model for thermal quenching, and equations for critical distance and decay time calculations.