Luminescent material
View Patent ↗According to one embodiment, the luminescent material exhibits a luminescence peak in a wavelength ranging from 490 to 580 nm when excited with light having an emission peak in a wavelength ranging from 250 to 500 nm. The luminescent material has a diffraction peak intensity of the largest peak detected at 2θ=30.1-31.1° that is higher than the diffraction peak intensity of the peak detected at 2θ=25.0-26.0° in X-ray diffraction by the Bragg-Brendano method using Cu-Kα line and its composition is represented by (Sr 1−x Eu x ) 3−y Al 3+z Si 13−z O 2+u N 21−w (a part of the Sr may be substituted by at least one selected from Ba, Ca, Mg and Na, 0<x≦1, −0.1≦y≦0.3, −3≦z≦−0.52, and −1.5≦u≦−0.3, −3<u−w≦1).
1. A luminescent material which exhibits an luminescence peak in a wavelength ranging from 490 to 580 nm when excited with light having an emission peak in a wavelength ranging from 250 to 500 nm and has a composition represented by Formula 1 below,
(M 1−x Eu x ) 3−y Al 3+z Si 13−z O 2+u N 21−w Formula 1
wherein M represents Sr and a part of the Sr may be substituted by at least one selected from Ba, Ca, Mg and Na; x, y, z, u, and u−w satisfy following conditions:
0<x≦1, −0.1≦y≦0.3, −3≦z≦−0.52
−1.5≦u≦−0.3, and −3<u−w≦1,
the luminescent material having a diffraction peak intensity (I 31 ) of the largest peak detected at 2θ=30.1-31.1° that is higher than a diffraction peak intensity (I 26 ) of the peak detected at 2θ=25.0-26.0° in X-ray diffraction by the Bragg-Brendano method using Cu-Kα line.
2. The luminescent material according to claim 1 , wherein x is 0.001≦x≦0.5.
3. The luminescent material according to claim 1 , wherein y is 0≦y≦0.25.
4. The luminescent material according to claim 1 , wherein z is −2≦z≦−0.52.
5. The luminescent material according to claim 1 , wherein u is −1≦u≦−0.3.
6. The luminescent material according to claim 1 , wherein u−w is −2≦u−w≦0.
7. The luminescent material according to claim 1 , wherein the luminescent material comprises a particle having a diameter of 5 to 61 μm.
8. The luminescent material according to claim 7 , wherein the particle has a diameter of 50 μm or less.
9. The luminescent material according to claim 8 , wherein the diameter is 40 μm or less.
10. The luminescent material according to claim 1 , wherein the luminescent material comprises a particle having an aspect ratio of 1 to 7.5.
11. The luminescent material according to claim 10 , wherein the aspect ratio is 2 to 7.
12. The luminescent material according to claim 11 , wherein the aspect ratio is 2 to 6.0.
13. The luminescent material according to claim 1 , wherein the luminescent material has at least ten peaks at diffraction angles (2θ) of 21.3-21.5°, 21.6-22.0°, 25.0-26.0°, 28.7-29.1°, 29.4-29.8°, 30.1-30.7°, 30.8-31.1°, 31.8-32.1°, 34.0-34.5°, 37.0-37.3°, 37.3-37.6°, 43.5-43.9°, 45.6-46.1°, 48.9-49.4°, 55.7-56.3°, 59.3-59.8°, and 62.8-63.2° in X-ray diffraction by the Bragg-Brendano method using Cu-Kα line.
14. The luminescent material according to claim 1 , wherein a ratio of the I 31 to I 26 (I 31 /I 26 ) is 1.1 to 8.
15. The luminescent material according to claim 14 , wherein the ratio I 31 /I 26 is 3 to 8.
16. A light-emitting device comprising:
alight-emitting element which emits light having an emission peak in a wavelength ranging from 250 to 500 nm; and
a luminous layer comprising a luminescent material which emits light by receiving light from the light-emitting element; the luminescent material which emits light comprising the luminescent material of claim 1 .
17. The light-emitting device according to claim 16 , further comprising a heat-dissipative insulation substrate on which the light-emitting element is placed.
18. The light-emitting device according to claim 16 , further comprising a luminous layer comprising a red-emitting luminescent material.
19. The light-emitting device according to claim 16 , wherein the light-emitting element emits light having a wavelength of 250 to 430 nm.
20. The light-emitting device according to claim 19 , further comprising a luminous layer comprising a red-emitting luminescent material, and a luminous layer comprising a blue-emitting luminescent material.