Dynamics of concentration quenching in Eu³⁺ and Tb³⁺ doped calcium dioxide-oxo-zirconium perovskite

The pure and doped calcium dioxide-oxo-zirconium (CaZrO₃) phosphors are synthesized by conventional solid state reaction technique. XRD analysis confirms the phase purity, homogeneity and crystalline nature of prepared phosphors. The FESEM and TEM micrographs show agglomerated clusters of particles with spherical symmetry and uniform grain connectivity. The elemental composition is well evident in EDX spectrum. The particle size analysis shows that as the doping concentration increases, the size of particles of synthesized phosphors also increases. The FTIR spectra discuss the molecular structure and bond activities of prepared samples. The PL spectroscopic studies show distinct emissions at 578, 595, 615 and 624 nm corresponding to hypersensitive transitions of Eu³⁺ and Tb³⁺ ions under 275 nm, UV excitation. The quenching of quantum yields with increase in doping confirms the occurrence of concentration quenching in the synthesized phosphors. The dynamics of energy transfer and concentration quenching are discussed in detail. The synthesized phosphors show drastically amended spectroscopic, structural and optical characteristics with varying doping concentration of rare earth impurities. The variable emissions with enhanced intensity confirm the color tunability of synthesized phosphors, proposing their applications in display devices, solid state lightings and other optical applications.