Selective transition manipulation and polarized luminescence in Sr₂Ca_0.9Eu_0.05Li_0.05MoO₆ double perovskite phosphor

Lanthanide-doped luminescent materials are widely used in fields such as lighting and optical sensing. The characteristic ⁵D₀→⁷F_J (J=0-4) transitions of Eu³⁺ are highly sensitive to the local crystal field symmetry and external excitation conditions. Achieving selective excitation and precise control of these specific transitions is crucial for the development of luminescent materials with tunable emission colors and high polarization. Double perovskite structured phosphors are ideal matrices for rare earth ion doped luminescence due to their stable crystal structure and adjustable lattice site symmetry. This study investigates the excitation-wavelength-dependent emission behavior and polarized optical properties of double perovskite structured phosphors Sr₂Ca_0.9Eu_0.05Li_0.05MoO₆ in the ultraviolet-visible region. Results indicate that tuning the excitation wavelength enables selective activation of different Eu³⁺ energy level transitions. Furthermore, by constructing a polarized optical test platform, we found significant differences in fluorescence intensity variations with changes in excitation and emission polarization angles. Notably, excitation polarization demonstrates superior efficacy in modulating Eu³⁺ luminescence intensity compared to emission polarization. This work provides direct experimental evidence for developing high-performance polarized luminescent materials and their applications in optoelectronic devices, such as three-dimensional displays and optical anti-counterfeiting.