Phosphor, method of producing the same, and light emitting apparatus

• US 8,663,498 B2
• Filed: 11/21/2007
• Issued: 03/04/2014
• Est. Priority Date: 11/24/2006
• Status: Active Grant

• Current Assignee: Denka Company Limited, GE Phosphors Technology, LLC (General Electric Company)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Masuda, Masatsugu, Terashima, Kenji
• Primary Examiner(s): Koslow, Carol M
• Assistant Examiner(s): Hoban, Matthew E
• Application Number:
  US11/944,052
• Publication Number:
  US 20080258602A1
• Time in Patent Office: 2,295 Days
• Field of Search: 252/301.4 R, 252/301.4 F, 313/503
• US Class Current: 252/301.4F
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 21/0826 Silicon aluminium oxynitrides, i.e. sialons
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• 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 2235/3865 Aluminium nitrides
• CPC Class Codes: C04B 2235/3873 Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
• CPC Class Codes: C04B 2235/442 Carbonates
• CPC Class Codes: C04B 2235/5454 nanometer sized, i.e. below 100 nm
• CPC Class Codes: C04B 2235/766 Trigonal symmetry, e.g. alpha-Si3N4 or alpha-Sialon
• CPC Class Codes: C04B 2235/767 Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites
• CPC Class Codes: C04B 35/581 based on aluminium nitride
• CPC Class Codes: C04B 35/584 : based on silicon nitride
• 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: C04B 35/62807 : Silica or silicates
• CPC Class Codes: C09K 11/0883 : Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7728 : containing europium
• CPC Class Codes: C09K 11/77348 : Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: F21K 9/64 : using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: G02F 1/1336 : Illuminating devices
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 : connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

There are provided a phosphor which is a divalent europium-activated oxynitride phosphor substantially represented by General formula (A): Eu_aSi_bAl_cO_dN_e, a divalent europium-activated oxynitride phosphor substantially represented by General formula (B): MI_fEu_gSi_hAl_kO_mN_n or a divalent europium-activated nitride phosphor substantially represented by General formula (C): (MII_l-pEu_p)MIIISiN₃, having a reflectance of light emission in a longer wavelength region of visible light than a peak wavelength of 95% or larger, and a method of producing such phosphor; a nitride phosphor and an oxynitride phosphor which emit light efficiently and stably by the light having a wavelength ranging from 430 to 480 nm from a semiconductor light emitting device by means of a light emitting apparatus using such phosphor, and a producing method of such phosphor; and a light emitting apparatus having stable characteristics and realizing high efficiency.

Claims

1. A phosphor comprising:

a divalent europium-activated oxynitride phosphor comprising a β

-type SiAlON substantially represented by Eu_aSi_bAl_cO_dN_e,

wherein 0.005≦

a≦

0.4, b+c=12, and d+e=16, and

wherein the phosphor has a reflectance of 95% or larger in a region of visible light wavelengths longer than the phosphor'"'"'s emission peak wavelength.

2. A method of producing the phosphor of claim 1, comprising the step of mixing aluminum nitride covered with fine particle silicon dioxide into a material for the phosphor.

3. The method of producing the phosphor according to claim 2, wherein said silicon dioxide that covers aluminum nitride has an average particle diameter of 10 to 200 nm, and occupies 0.01 to 15% by weight relative to aluminum nitride.

4. The method of producing the phosphor according to claim 2, wherein materials for the phosphor are mixed in an inert atmosphere without using an apparatus for mechanical grinding.

5. A light emitting apparatus comprising a light emitting device that emits primary light, and a light converter that absorbs part of said primary light and emits secondary light having a longer wavelength than that of said primary light, wherein said light converter includes a green-based luminous phosphor

comprising a β

-type SiAlON substantially represented by

Eu_aSi_bAl_cO_dN_e,

wherein 0.005≦

a≦

0.4, b+c=12, and d+e=16 , and wherein said green-based luminous phosphor comprises a divalent europium-activated oxynitride phosphor having a reflectance of 95% or larger in a region of visible light wavelengths longer than the phosphor'"'"'s emission peak wavelength.

6. The light emitting apparatus according to claim 5, wherein said light emitting device is a gallium nitride-based semiconductor device, and primary light from the light emitting device has a wavelength ranging from 430 to 480 nm.