1：Experimental Design and Method Selection:

The study uses a sol-gel method for sample synthesis, with structural characterization via XRD, elemental mapping via SEM, and luminescence measurements via spectrophotometry. The rate equation model is applied to calculate ET and CR coefficients.

2：Sample Selection and Data Sources:

Samples with formula (YbxEr0.02Gd0.98-x)2Ce2O7 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) are synthesized. Data include XRD patterns, UC spectra, decay curves, and temperature-dependent emissions.

3：02Gd98-x)2Ce2O7 (x = 0, 02, 04, 06, 08, 1) are synthesized. Data include XRD patterns, UC spectra, decay curves, and temperature-dependent emissions. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment includes Bruker D8 Advance X-ray diffractometer, Tecnai G2 F20 SEM, Agilent 7700 ICP-AES, FLS980 spectrophotometer, laser diodes, pulse tunable laser, flash lamp, PMT detectors, and fluoroSENS-2000 spectrophotometer. Materials include Gd2O3, Yb2O3, Er2O3, CeO2 (all 99.99% purity).

4：99% purity). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Samples are synthesized, characterized for phase purity and structure, then UC spectra, decay curves, and temperature-dependent emissions are measured under specific excitations (e.g., 980 nm LD). Data are analyzed using rate equations and fitting methods.

5：Data Analysis Methods:

Data analysis involves solving rate equations, exponential decay fitting, power dependence analysis (I ∝ P^n), and fluorescence intensity ratio calculations for temperature sensing.