| 摘要 |
A silicate-based phosphor is provided to solve problems of the conventional garnet-based phosphor or silicate-based phosphor comprising YAG:Ce(3+) and to produce a light emitting device having high color temperature and color rendering index. A silicate-based phosphor has a composition represented by the formula of (4-x-y-z)SrO.xBaO.zCaO.aMgO.2(SiO2) .bM2O3 : yEu, wherein M is at least one metal selected from the group consisting of Y, La, Ce, Nd, Gd, Tb, Yb, and Lu, 0<x<=3.95, 0<y<=1, 0<=z<3.95, x+y+z<4, 0<a<2, and 0<b<1. A method for preparing the silicate-based phosphor includes the steps of: (a) mixing an oxide, nitride, or carbonate of an alkali earth metal containing Ba as an essential component, SiO2, an oxide, nitride, or halogenide of a rare earth metal, and an oxide, nitride, or halogenide of Eu as an activator under NH4F, BaF2, CaF2, or MgF2 solvent as a flux; (b) drying the mixture at 50-150 °C for 3 minutes to 24 hours; (c) heat-treating the dried material at 800-1500 °C under a reduction atmosphere for 1-48 hours; (d) grinding the obtained phosphor to obtain phosphor powder having a predetermined size; and (e) washing the phosphor powder with a solvent to remove an unreacted material.
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