COMPOSITE PARTICLE FOR YAG PHOSPHOR, YAG PHOSPHOR AND LIGHT-EMITTING DEVICE

摘要

To provide a phosphor having a temperature extinction property in a higher level than that of a phosphor obtained by a ball-mill process, and composite particles for a YAG phosphor suitable for the production of the above phosphor.SOLUTION: The composite particles for a YAG phosphor comprise Y and Al and at least one dopant selected from the group consisting of Ce, Tb, Eu, Yb, Pr, Tm and Sm, and are characterized in that: (i) when the composite particles are subjected to EDX analysis to study an in-plane distribution of a Y-domain intensity and to obtain a frequency distribution of independent regions having the Y-domain intensity of 50% or more with respect to the area, an area where the cumulative frequency of the independent regions in the frequency distribution reaches 70% is 120000 nmor less; or (ii) when a grayscale histogram having 0 to 255 gradation levels is obtained from an ESB image of the composite particles, the percentage of 170 to 255 gradation levels in the histogram is 40% by area or more in the whole area.SELECTED DRAWING: Figure 1