Synthesis,characterization and photoluminescence of Eu3+, Ce3+ co-doped CaLaAl3O7 phosphors

Powder phosphors of CaLa_{1? x} Eu _x Al₃O₇, CaLa_{1? x} Ce _x Al₃O₇ and CaLa_{0.99? x} Eu _x Ce_0.01Al₃O₇, where x = 0.01, 0.03, 0.05 and 0.07, were prepared by a combustion method. The powders were well characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence techniques. Emission spectra of Eu³⁺-doped powder phosphors showed strong red emission at 613 nm (⁵D₀ → ⁷F₂); no concentration quenching was observed. Generally, Ce³⁺ acts as an efficient sensitizer when doped with other trivalent lanthanide ions. However, interestingly, in the CaLaAl₃O₇ powder phosphors, the addition of Ce³⁺ with Eu³⁺ exhibited an adverse effect–decreased photoluminescence intensity. The reasons for this behavior are discussed.