Synthesis and luminescence properties of Ca _3Ga _2Si _3O _(12):RE ~(3+) (RE = Eu/Tb) powder phosphors

摘要

Rare earth ions (Eu ~(3+) or Tb ~(3+))-activated Ca _3 Ga _2 Si _3O _(12) (CaGaSi) phosphors were synthesized by using a sol-gel method. Photoluminescence spectra of Eu ~(3+):CaGaSi phosphors exhibited five emission bands at 578, 592, 612, 652 and 701 nm, which were assigned to the transitions (~5D _0 → ~7F _0, ~7F _1, ~7F _2, ~7F _3 and ~7F _4), respectively, with an excitation wavelength of λ _(exci) = 392 nm. Among these, the transition ~5D _0 → ~7F _2 (612 nm) displayed bright red emission. In the case of Tb ~(3+):CaGaSi phosphors, four emission bands were observed at 488 (~5D _4 → ~7F _6), 543 (~5D _4 → ~7F _5), 584 (~5D _4 → ~7F _4) and 614 nm (~5D _4 → ~7F _3) from the measurement of PL spectra with λ _(exci) = 376 nm. Among these, the transition ~5D _4 → ~7F _5 at 543 nm displayed bright green emission. The structure and morphology of the phosphors were studied from the measurements of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX) results.