FLUORESCENT POWDER, PREPARATION METHOD FOR FLUORESCENT POWDER, AND LIGHT EMITTING DEVICE HAVING FLUORESCENT POWDER

摘要

Fluorescent powder, a preparation method for the fluorescent powder, and a light emitting device having the fluorescent powder. The fluorescent powder comprises an inorganic compound which at least comprises an element M, an element A, an element D, and an element R; the element M is one or two elements selected from the group consisting of Lu, La, Pr, Nd, Sm, Y, Tb, and Gd and must comprise Lu; the element A is Si and/or Ge; the element D is one or two elements selected from the group consisting of O, N, and F and must comprise N; the element R is Ce and/or Dy. Since the ionic radius of Lu³⁺ is smaller than that of La³⁺, when the inorganic compound comprises element Lu, the original ligand site would be contracted. In order to reduce lattice distortion due to the ligand site contraction, the adjacent ligand site expands, which weakens the existing crystal field environment, so that the photochromic property of the fluorescent powder can be flexibly adjusted according to needs; furthermore, the thermal stability of the fluorescent powder is good.