Enhanced Eu³⁺ emission in Ca₂LaTaO₆:Eu³⁺ phosphors by codoping Bi³⁺

Abstract

The Bi³⁺/Eu³⁺ singly and codoped double perovskite Ca₂LaTaO₆ phosphors were made via solid-phase sintering with the addition of H₃BO₃. X-ray powder diffraction patterns, morphology, particle size, and photoluminescence properties of them were researched. All of Bi³⁺/Eu³⁺ singly and codoped Ca₂LaTaO₆ phosphors have the same phase with pure Ca₂LaTaO₆. And all of phosphors have similar morphology and particle size. Exciting at 275 nm, Ca₂La_1−xEu_xTaO₆ (x = 0.1, 0.2, 0.3, 0.4, and 0.5) phosphors exhibit bands resulting from ⁵D₀ → ⁷F_J (J = 0, 1, 2, 3, and 4) transitions of Eu³⁺. It is found that the critical doping concentration of Eu³⁺ in Ca₂LaTaO₆ is about 0.4. Exciting at 272 nm, Ca₂La_1−yBi_yTaO₆ (y = 0.05, 0.1, and 0.15) phosphors exhibit emission bands corresponding to the ³P₁ → ¹S₀ transition of Bi³⁺. There is the occurrence of energy transfer in Bi³⁺/Eu³⁺ codoped Ca₂LaTaO₆ phosphors, which benefits to the enhancement of Eu³⁺ emission intensity.