1：Experimental Design and Method Selection:

The phosphors were synthesized using the high-temperature solid-state reaction method under a weak reducing atmosphere (5%H2/95%N2). Characterization involved X-ray diffraction (XRD) for phase analysis and photoluminescence (PL) spectroscopy for emission and excitation studies.

2：2). Characterization involved X-ray diffraction (XRD) for phase analysis and photoluminescence (PL) spectroscopy for emission and excitation studies. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples with compositions Na3-xLuSi2O7:xCe3+ (x=

3：01–07) and Na95-yLuSi2O

4：05Ce3+,yTb3+ (y=01,03,05,07,09) were prepared from raw materials including Na2CO3, SiO2, Lu2O3, Tb4O7, and CeOList of Experimental Equipment and Materials:

Equipment included a Rigaku D/max-II B diffractometer for XRD, a Hitachi F-7000 luminescence spectrophotometer for PL measurements, and a tube furnace for sintering. Materials were analytical or high-purity reagents.

5：Experimental Procedures and Operational Workflow:

Raw materials were weighed, ground with ethanol, sintered at 1200°C for 4 hours in a reducing atmosphere, furnace-cooled, and crushed into powders for characterization. XRD was performed with Cu Kα radiation, and PL spectra were measured using a xenon lamp excitation.

6：Data Analysis Methods:

Data analysis included Rietveld refinement for structural parameters, Gaussian fitting of emission spectra, calculation of energy transfer efficiency and critical distances using established formulas, and CIE chromaticity diagram analysis for color coordinates.