Luminescence Properties of Ce³⁺ Doped Garnet Ca₂LaZr₂Al₃O₁₂ Phosphors

A series of novel Ca₂LaZr₂Al₃O₁₂: xCe³⁺garnet phosphors were obtained by conventional high temperature solid-state reaction. Crystal structure, phase purity, micromorphology as well as luminescence properties are studied via X-ray powder diffraction, scanning electron microscope and photoluminescence spectra including excitation and emission. Moreover, the mechanism of concentration quenching, thermal stability, fluorescent lifetime and quantum efficiency were investigated in detail. Under n-UV excitation, Ca₂LaZr₂Al₃O₁₂: Ce³⁺ exhibits a broadband of blue emission at 440 nm approximately for maximum, corresponding to 5d-4f transition of Ce³⁺. Emission can keep 41% of initial intensity when temperature is promoted to 373 K according to temperature-dependence emission spectra. The internal quantum efficiency of the optimal specimen is 15% and with Ce³⁺ increasing, the color of emission transfers to light from dark blue at CIE. (paper)