1：Experimental Design and Method Selection:

The study involved growing Li2WO4 single crystals using the vertical Bridgman method, followed by detailed characterization of phase, FTIR spectra, thermal behavior, optical transmission, and luminescence properties at various temperatures. Theoretical models for emission linewidth broadening were applied.

2：Sample Selection and Data Sources:

Polycrystalline materials were synthesized from LiOH and WO3 powders via solid-state reaction. Single crystals were grown in a platinum crucible. Samples with thicknesses of 2.0 mm, 4.0 mm, and 6.0 mm were prepared for analysis.

3：0 mm, 0 mm, and 0 mm were prepared for analysis. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included XRD (D/Max-2550V, Rigaku), FTIR spectrometer (Nicolet 6700), TG/DTA (Pyris Diamond), UV-VIS-NIR spectrometer (Lambda 950, Perkin Elmer), fluorescence spectroscopy (FLS980, Edinburgh), and a spectrum analyzer with liquid helium cooling. Materials included LiOH (99.9 wt%), WO3 (99.9 wt%), and a platinum crucible.

4：9 wt%), WO3 (9 wt%), and a platinum crucible. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Polycrystalline synthesis involved grinding and sintering at 600°C and 700°C. Crystal growth was performed in a Bridgman furnace at 842–850°C with a lowering rate of 0.5–1.0 mm/h. Characterization steps included XRD for phase identification, FTIR for chemical groups, TG/DTA for thermal analysis, transmission spectra measurement, luminescence spectra acquisition from 30 K to 300 K using a 355 nm laser, and decay time measurements.

5：5–0 mm/h. Characterization steps included XRD for phase identification, FTIR for chemical groups, TG/DTA for thermal analysis, transmission spectra measurement, luminescence spectra acquisition from 30 K to 300 K using a 355 nm laser, and decay time measurements. Data Analysis Methods:

5. Data Analysis Methods: Data were analyzed using fitting models for emission linewidth (Equation 1 involving inhomogeneous broadening, LO phonon scattering, and impurity scattering) and decay times. Statistical analysis included chi-squared values for decay time fits.