1：Experimental Design and Method Selection

The study synthesized Cs2BF6:Mn4+ phosphors via a precipitation‐cation exchange route, characterized their phase purity, morphology, and optical properties using XRD, SEM, and PL spectra. Temperature-dependent PL was used to study emission mechanisms.

2：Sample Selection and Data Sources

Samples were prepared with varying Mn4+ doping concentrations in Cs2BF6 (B = Ge, Si, Zr, Ti) matrices. Data were collected from synthesized phosphors and fabricated WLED devices.

3：List of Experimental Equipment and Materials

X-ray diffraction (XRD) patterns were performed on a D8 Focus diffractometer (Bruker). Morphology was characterized by a FE-SEM (S-4800, Hitachi). PL spectra were collected by an FLS-920 spectrometer. Materials included GeO2, HF, CsF, and K2MnF6 precursor.

4：Experimental Procedures and Operational Workflow

The synthesis involved dissolving GeO2 in HF, adding CsF to precipitate Cs2GeF6, then adding K2MnF6 for cation exchange. The product was washed, dried, and characterized. WLEDs were fabricated by coating resin colloid mixed with phosphors onto blue LED chips.

5：Data Analysis Methods

Data analysis included fitting luminescence decay curves to a second-order exponential decay model and calculating quantum efficiencies. The relationship between emission intensity and temperature was analyzed using empirical formulas.