CPC C09K 11/77346 (2021.01) [C09K 11/7706 (2013.01); C09K 11/77348 (2021.01); F21S 43/16 (2018.01); H01L 33/504 (2013.01); H01L 33/58 (2013.01)] | 16 Claims |
1. An image display device, comprising a light-emitting device as a light source,
wherein the light-emitting device comprises a first light emitter, and a second light emitter that emits visible light due to irradiation with light from the first light emitter, and the second light emitter includes a phosphor that includes a crystal phase having a composition represented by formula [2] below,
RexMAaMBb(MC′1-yMDy)cNdXe [2]
wherein in formula [2] above,
MA includes one or more elements selected from the group consisting of Sr, Ca, Ba, Na, K, Y, Gd, and La,
MB includes one or more elements selected from the group consisting of Li, Mg, and Zn, MC′ is Al,
MD includes one or more elements selected from the group consisting of Si, Ga, In, and Sc,
X includes one or more elements selected from the group consisting of F, Cl, Br, and I,
Re includes one or more elements selected from the group consisting of Eu, Ce, Pr, Tb, and Dy, and
a, h, c, d, e, x, and y satisfy the following expressions, respectively,
0.7≤a≤1.3
0.7≤b≤1.3
2.4≤c≤3.6
3.2≤d≤4.8
0.0≤e≤0.2
0.0<x≤0.2
0.0<y≤1.0)
wherein, when the intensity of a peak that appears in a region where 2θ=38-39° in a powder X-ray diffraction spectrum of the phosphor is designated Ix and the intensity of a peak that appears in a region where 2θ=37-38° is designated Iy, the relative intensity Ix/Iy of Ix to Iy is 0.140 or less, and
wherein the phosphor has a long emission peak wavelength of from 630 to 660 nm in an emission spectrum.
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