1：Experimental Design and Method Selection:

The study uses a hydrothermal method to synthesize KYb2F7 nanoparticles co-doped with Er3+ and Sc3+. The rationale is to explore the effects of non-luminescent center doping on luminescence properties. Theoretical models include energy transfer mechanisms involving Yb3+, Er3+, and Sc3+ ions.

2：3+. The rationale is to explore the effects of non-luminescent center doping on luminescence properties. Theoretical models include energy transfer mechanisms involving Yb3+, Er3+, and Sc3+ ions. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples are prepared with varying concentrations of Er3+ (1%, 1.5%, 2%, 2.5%) and Sc3+ (0%, 5%, 10%, 15%, 20%), with total rare earth ions fixed at 2 mmol. Data sources include synthesized nanocrystals characterized by XRD, TEM, XPS, and fluorescence spectroscopy.

3：5%, 2%, 5%) and Sc3+ (0%, 5%, 10%, 15%, 20%), with total rare earth ions fixed at 2 mmol. Data sources include synthesized nanocrystals characterized by XRD, TEM, XPS, and fluorescence spectroscopy. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment includes a D/Max-R X-ray diffractometer (Japanese science), JEOL-2100 transmission electron microscope, Horiba F-max fluorescence spectrometer with a 980 nm NIR laser. Materials include KOH, deionized water, ethanol, oleic acid, KF·2H2O, YbCl3·6H2O, ErCl3·6H2O, ScCl3·6H2O.

4：2O. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Dissolve KOH in water, add ethanol and oleic acid, stir, add KF·2H2O, stir, add rare earth chloride solution, stir, transfer to container, heat at 220°C for 24h, cool, wash with ethanol and water, dry. Characterize using XRD, TEM, XPS, and measure UC fluorescence spectra.

5：Data Analysis Methods:

XRD patterns compared to JCPDS standards, TEM for morphology, XPS for chemical states, fluorescence spectra analyzed for intensity and photon processes using logarithmic fitting for excitation power dependence.