Synthesis, photophysical and spectroscopy properties of mixed lanthanide metal ions complexes emitting white light under the influence of ancillary ligand

This study reports on synthesizing a series of [Eu_xTb_1-x.L₃.Bipyl] complexes using the solution precipitation method. Energy dispersive X-ray analysis (EDAX) was used to determine the purity of the complexes. The nature and morphology of synthesized complexes were investigated using elemental analysis, X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FE SEM) techniques. In forecasting tuning of color, photoluminescent excitation (PL) and photoluminescent emission (PLE) spectra were studied as a function of the concentration of Eu³⁺ and Tb³⁺ ions. Radiative rate (A_rad), JO intensity parameters (Ω_λ) and quantum efficiency (φ) are also calculated. Urbach energy, optical band gap, and Refractive index measurements suggest that these complexes should be used in solar cell devices and semiconductors. The calculated Commission International de I'Eclairage 1931 (CIE) coordinates (x,y) show that the color can be tuned to near white light (x = 0.3033, y = 0.3381). To achieve this, complexes with different concentrations of Eu³⁺ and Tb³⁺ ions were analyzed. It has great potential as an excellent color-tunable luminescent material for solid-state lighting and displays.