COMBUSTION SYNTHESIS AND OPTICAL PROPERTIES OF Eu3+, Al3+ CO-DOPED CeO2 PHOSPHOR

Abstract

This paper reports the effect of Al³⁺ content on luminescence properties of CeO₂:Eu³⁺, Al³⁺ phosphor was successfully synthesized using solution combustion followed by annealed at high temperature. The crystal structure, chemical element composition, morphology, and photoluminescence properties of the phosphors were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and luminescence analysis. The XRD results confirmed the formation of the single-phase cubic CeO₂ with high crystallinity. SEM analysis exhibited cubic-like particle morphology with an average size of about 30 nm. Under 393 nm excitation, the phosphors emitted intense orange-red emissions at 595, 615/631, 650, and 700 nm, corresponding to the ⁵D₀ → ⁷F_j (j = 1, 2, 3, 4) transitions of Eu³⁺, respectively. Significantly, the orange-red emission intensity of the Al³⁺ doped sample was significantly enhanced compared to the un-doped sample. This phenomenon is due to the presence of Al³⁺ on CeO₂:Eu³⁺, Al³⁺ phosphor formed oxygen vacancy and destroyed the symmetry of the crystal field of host lattice. These results suggested that the CeO₂: Eu, Al phosphor is suitable for optoelectronic applications.