Extensive studies of host lattices and activators in lanthanide phosphors based on efficient synthesis

Uniform and dispersive NaLa(MoO4)2-x(WO4)x (abbreviated as NLMW): Eu3+/Tb3+(5 mol%) microspheres were successfully synthesized at low temperature (393 K). The incorporation of Bi3+ or Mn2+ into CaMoO4: Eu3+ with tetragonal crystalline phase has also been studied. The structure, morphology, and luminescent properties of these powder samples were examined by means of X-ray diffraction (abbreviated as XRD), scanning electron microscopy (abbreviated as SEM), and fluorescent spectrophotometry, respectively. SEM images substantiated that these phosphors have uniform sphere-shaped morphologies. The samples exhibited the characteristic emission of Eu3+(5D0 → 7FJ)/Tb3+(5D4 → 7FJ) under ultraviolet excitation. Effects of the ratio of MoO4/WO4 on the luminescence behavior were investigated in detail. The MoO4/WO4 ratio was optimized as 1/1. The international commission on illumination (abbreviated CIE for its French name) chromaticity coordinates of NLMW: Eu3+ and NLMW: Tb3+ indicate the emissions were located in the red and green region, which will be beneficial for the potential device fabrication. Encapsulation of Bi3+ and Mn2+ both can effectively sensitize europium (III) ions, generating stronger red emissions (5D0 → 7FJ).