1：Experimental Design and Method Selection:

Synthesis of ligands H2L1 and H2L2, and their lanthanide complexes via reaction with lanthanide hydroxides in ethanol or ethanol-acetonitrile solutions. Structural characterization using single crystal and powder X-ray diffraction, photoluminescence spectroscopy, diffuse reflection spectroscopy, and thermal analysis. OLED fabrication using spin-coating and thermal deposition methods.

2：Sample Selection and Data Sources:

Lanthanide ions (Lu, Yb, Er, Gd, Eu, Sm) and ligands H2L1 and H2L2 were used. Data from elemental analysis, IR spectra, XRD, and spectroscopy measurements.

3：List of Experimental Equipment and Materials:

Bruker D8 Advance Vario diffractometer, PerkinElmer LAMBDA 950 spectrometer, Edinburgh Instruments FLS980 Fluorescence Spectrometer, Ocean Optics S2000 spectrometer, nitrogen laser LGI-21, spin coater KW-4A, thermal deposition system, cryostat KP-15 M, temperature controller BTP-3, voltmeter V7-

4：Materials include lanthanide hydroxides, ethanol, acetonitrile, PEDOT:

PSS, PVK, TPBi, LiF, Al.

5：Experimental Procedures and Operational Workflow:

Synthesis of complexes, crystallization, XRD measurements, photoluminescence and electroluminescence measurements at various temperatures, OLED device fabrication and testing.

6：Data Analysis Methods:

Rietveld refinement for structure determination, Mott-Seitz model for temperature dependence analysis, quantum yield calculations using radiative lifetimes, sensitivity calculations for thermometry.