Photoluminescence properties of Ca₂ Al₂ O₅ :RE³⁺ (RE = Eu, Dy and Tb) phosphors for solid state lighting

Ca₂ Al₂ O₅ :Eu³⁺ , Ca₂ Al₂ O₅ :Dy³⁺ and Ca₂ Al₂ O₅ :Tb³⁺ phosphors were synthesized using a combustion synthesis method. The prepared phosphors were characterized by X-ray powder diffraction for phase purity, by scanning electron microscopy for morphology, and by photoluminescence for emission and excitation measurements. The Ca₂ Al₂ O₅ :Eu³⁺ phosphors could be efficiently excited at 396 nm and showed red emission at 594 nm and 616 nm due to ⁵ D₀  → ⁷ F₁ and ⁵ D₀  → ⁷ F₂ transitions. Dy³⁺ -doped phosphors showed blue emission at 482 nm and yellow emission at 573 nm. Ca₂ Al₂ O₅ :Tb³⁺ phosphors showed emission at 545 nm when excited at 352 nm. Concentration quenching occurred in both Eu³⁺ and Dy³⁺ phosphors at 0.5 mol%. Photoluminescence results suggested that the aluminate-based phosphor could be a potential candidate for application in environmentally friendly based lighting technologies.