Phosphor and use thereof

• US 8,703,019 B2
• Filed: 05/22/2012
• Issued: 04/22/2014
• Est. Priority Date: 05/24/2005
• Status: Active Grant

• Current Assignee: Independent Administrative Institution National Institute For Materials Science, Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Independent Administrative Institution National Institute For Materials Science, Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Hirosaki, Naoto, Seto, Takatoshi, Kijima, Naoto
• Primary Examiner(s): Koslow, Carol M
• Application Number:
  US13/477,421
• Publication Number:
  US 20120262648A1
• Time in Patent Office: 700 Days
• Field of Search: 252/301.4 F, 252/301.6 F, 257/98, 313/486, 313/487, 313/503, 313/582, 313/584, 313/467
• US Class Current: 252/301.4F
• CPC Class Codes: C01B 21/0602 with two or more other elements chosen from metals, silicon or boron
• CPC Class Codes: C01B 21/0821 Oxynitrides of metals, boron or silicon
• CPC Class Codes: C01B 21/0823 Silicon oxynitrides
• CPC Class Codes: C01B 21/0826 Silicon aluminium oxynitrides, i.e. sialons
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/386 Boron nitrides
• CPC Class Codes: C04B 2235/3865 Aluminium nitrides
• CPC Class Codes: C04B 2235/3878 Alpha silicon nitrides
• CPC Class Codes: C04B 2235/3895 Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/40 Metallic constituents or additives not added as binding phase
• CPC Class Codes: C04B 2235/401 Alkaline earth metals
• CPC Class Codes: C04B 2235/402 Aluminium
• CPC Class Codes: C04B 2235/428 Silicon
• CPC Class Codes: C04B 2235/46 Gases other than oxygen used as reactant, e.g. nitrogen used to make a nitride phase
• CPC Class Codes: C04B 2235/5409 expressed by specific surface values
• CPC Class Codes: C04B 2235/5445 : submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/656 : characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 : Heating rate
• CPC Class Codes: C04B 2235/6582 : Hydrogen containing atmosphere
• CPC Class Codes: C04B 2235/761 : Unit-cell parameters, e.g. lattice constants
• CPC Class Codes: C04B 35/581 : based on aluminium nitride
• CPC Class Codes: C04B 35/593 : obtained by pressure sintering
• CPC Class Codes: C04B 35/597 : based on silicon oxynitride, e.g. SIALONS
• CPC Class Codes: C04B 35/6262 : of calcined, sintered clinker or ceramics
• CPC Class Codes: C09K 11/0883 : Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77218 : Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/77348 : Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/77928 : Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials

Abstract

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′_pM^II′_1−pM^III′M^IV′N₃).a(M^IV′_(3n+2)/4N_nO).b(AM^IV′₂N₃)  [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.

Claims

1. A phosphor comprising a crystal phase having a chemical composition expressed by the general formula [31]:

(Eu_yM^II<sub>1−

y</sub>M^IIIM^IVN₃)<sub>1−

x′</sub>

(AM^IV₂N₃)_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.