Fabrication and Luminescence Properties of Ca_2Gd_8 (SiO_4 )_6O_2: Er~(3+) Phosphors via Sol-Gel Process

摘要

Ca_2RE_8(SiO_4)_6O_2(RE = Y, Gd, La) is a kind of ternary rare-earth-metal silicate with the oxyapatite structure, which was used as host materials for the luminescence of various rare earth and mercury-like ions. Ca_2Gd_8(SiO_4)_6O_2:Er~(3+) phosphors were prepared through the sol-gel process. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicate that the phosphors crystallized completely at 1000 ℃. SEM study reveals that the average grain size is 400 ～ 1000 nm. In Ca_2Gd_8 (SiO_4)_6O_2 : Er~(3+) phosphors, the Er~(3+) shows its characteristic green emission at 528 nm (~2H_(11/2)-~4I_(15/2)) and 548 nm (~4S_(3/2)-~4I_(15/2)) upon excitation into 382 nm, with an optimum doping concentration of 5% (mole fraction) of Gd~(3+) in the host lattices.