Phosphor and use thereof
View Patent ↗A phosphor which emits light having high brightness, serves as an excellent orange or red phosphor whose light brightness is less decreased when exposed to an excitation source contains a crystal phase having the chemical composition expressed by the general formula [1]: (1− a−b )(Ln′ p M II′ 1−p M III′ M IV′ N 3 ). a (M IV′ (3n+2)/4 N n O). b (AM IV′ 2 N 3 ) [1] wherein Ln′ represents a metal element selected from the group consisting of lanthanoids, Mn, and Ti; Mn II′ represents a divalent metal element except the Ln′ element; M III′ represents a trivalent metal element; M IV′ represents a tetravalent metal element; A represents a metal element selected from the group consisting of Li, Na, and K; 0<p≦0.2; 0≦a, 0≦b, a+b>0, 0≦n, and 0.002≦(3n+2)a/4≦0.9.
1. A phosphor comprising a crystal phase having a chemical composition expressed by the general formula [31]:
(Eu y M II 1−y M III M IV N 3 ) 1−x′ (AM IV 2 N 3 ) x′ [31]
wherein in the general formula [31], M II represents divalent metal elements including Mg, Ca, Sr, Ba, and Zn at a ratio of 90 mol % or more in total; M III represents trivalent metal elements including Al at a ratio of 80 mol % or more; M IV represents tetravalent metal elements including Si at a ratio of 90 mol % or more; A represents one or more metal elements selected from Li, Na, and K; x′ satisfies 0<x′<1.0; y satisfies 0<y 0.2.
2. The phosphor according to claim 1 , wherein in the general formula [31], M II includes Ca and Sr at a ratio of 80 mol % or more in total.
3. The phosphor according to claim 1 , wherein in the general formula [31], M II is Ca, M III is Al, and M IV is Si.
4. A light emitting device comprising a first illuminant which emits light having a wavelength of 330 nm to 500 nm, and a second illuminant which emits visible light upon irradiation with light from the first illuminant, wherein the second illuminant contains the phosphor according to claims 1 .
5. The light emitting device according to claim 4 , wherein the first illuminant is a laser diode or light emitting diode.
6. The light emitting device according to claim 5 , wherein the first illuminant is a light emitting diode which emits light having a wavelength of 330 nm to 420 nm, and the second illuminant is composed of the phosphor, which emits red light, a blue phosphor which emits fluorescence exhibiting an emission peak in the wavelength from 420 nm to 500 nm upon excitation with light having a wavelength of 330 nm to 420 nm, and a green phosphor which emits fluorescence exhibiting an emission peak in the wavelength from 500 nm to 570 nm upon excitation with light having a wavelength of 330 nm to 420 nm, and the red, green, and blue light are mixed thereby producing white light.
7. The light emitting device according to claim 5 , wherein the first illuminant is a light emitting diode which emits light having a wavelength of 420 nm to 500 nm, and the blue light emitted from the light emitting diode is mixed with light emitted from the phosphor upon excitation with a light from the first illuminant thereby producing white light.
8. The light emitting device according to claim 5 , wherein the first illuminant is a light emitting diode which emits light having a wavelength of 420 nm to 500 nm, the second illuminant is composed of the phosphor, and a green phosphor which emits fluorescence exhibiting an emission peak in the wavelength from 500 nm to 570 nm upon excitation with light having a wavelength of 420 nm to 500 nm, and thus the light emitting device emits a white light.
9. The light emitting device according to claim 5 , wherein the first illuminant is a light emitting diode which emits light having a wavelength of 420 nm to 500 nm, the second illuminant is composed of the phosphor, and a yellow phosphor which emits fluorescence exhibiting an emission peak in the wavelength from 550 nm to 600 nm upon excitation with light having a wavelength of 420 nm to 500 nm, and thus the light emitting device emits a white light.
10. A lighting system comprising the light emitting device according to claim 4 .
11. A display having an excitation source and a phosphor, wherein the phosphor includes at least the phosphor according to claims 1 .
12. A display comprising the light emitting device according to claim 4 .