1：Experimental Design and Method Selection:

The study employed a high-temperature solid-state method to synthesize Dy3+ doped Sr2CaWO6 phosphors. The design rationale was to investigate the photoluminescence properties and energy transfer mechanisms by varying Dy3+ concentration and introducing charge compensators. Theoretical models included the use of the Blasse equation for critical distance calculation and Van Uitert's model for multipolar interaction analysis.

2：Sample Selection and Data Sources:

Samples were prepared with Sr2Ca(1?

3：5x%)WO

x mol% Dy3+ (x = 0,

4：1, 3, 5, 0, 5, 0, 0) and Sr2Ca99WO

0.5 mol% Dy3+, 0.5 mol% M+ (M+ = Li+, Na+, K+). Data sources included XRD patterns, UV-Vis absorption spectra, excitation and emission spectra, and lifetime measurements.

5：5 mol% Dy3+, 5 mol% M+ (M+ = Li+, Na+, K+). Data sources included XRD patterns, UV-Vis absorption spectra, excitation and emission spectra, and lifetime measurements. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included a Rigaku D/MAX 2550 diffractometer, Perkin-Elmer Lambda 950 UV-Vis spectrometer, Edinburgh Instruments FS5 photoluminescence spectrometer, and FLS-980 fluorometer. Materials were SrCO3 (99.9%, Sigma-Aldrich), CaCO3 (99.95–100.05%, Alfa), WO3 (99.90%, Adamas), Li2CO3 (99%, Alfa), Na2CO3 (99.8%, General-Reagent), K2CO3 (99%, Sigma-Aldrich), and Dy2O3 (99.99%, Adamas).

6：9%, Sigma-Aldrich), CaCO3 (95–05%, Alfa), WO3 (90%, Adamas), Li2CO3 (99%, Alfa), Na2CO3 (8%, General-Reagent), K2CO3 (99%, Sigma-Aldrich), and Dy2O3 (99%, Adamas). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Starting materials were mixed, ground, preheated at 850°C for 5 h, calcined at 1200°C for 12 h, and reground. XRD data were collected from 10° to 70° 2θ. UV-Vis absorption, excitation, and emission spectra were measured with specified instruments. Lifetime was measured with an FLS-980 fluorometer.

7：2θ. UV-Vis absorption, excitation, and emission spectra were measured with specified instruments. Lifetime was measured with an FLS-980 fluorometer. Data Analysis Methods:

5. Data Analysis Methods: Data analysis involved calculating optical band gaps using the Tauc plot method, critical distance using Blasse's equation, and multipolar interaction using Van Uitert's model. Chromaticity coordinates were determined from emission spectra.