Synthesis, Crystal Structures, and Photoluminescence Properties of Ce³⁺-Doped Ca₂LaZr₂Ga₃O₁₂: New Garnet Green-Emitting Phosphors for White LEDs

A new family of garnet compounds, Ca₂LnZr₂Ga₃O₁₂ (Ln = La, Y, Lu, Gd) have been synthesized by high-temperature solid-state reaction method. The crystal structures were characterized by the X-ray diffraction (XRD) and refined by the Rietveld method. The photoluminescence properties, morphology, CIE value, quantum efficiency, and thermal stability of Ca₂LaZr₂Ga₃O₁₂:Ce³⁺ phosphors were investigated in detail to evaluate the use in w-LEDs. The photoluminescence results revealed that these phosphors have a broad excitation band in the blue region ranging from 400 to 470 nm and a broad green emission band centered at about 515 nm. The above results indicated that the phosphors could be effectively excited by blue light and may have the potential to serve as green-emitting phosphors for application in w-LEDs.