Light emitting device having a divalent europium-activated alkaline earth metal orthosilicate phoshor

• US 20100155761A1
• Filed: 02/23/2010
• Published: 06/24/2010
• Est. Priority Date: 12/28/2000
• Status: Abandoned Application

• Current Assignee: Leuchstoff Breitungen GmbH, Litec Gbr, Toyoda Gosei Company Limited (Toyota Motor Corporation), Tridonic Optoelectronics GmbH
• Original Assignee: Leuchstoff Breitungen GmbH, Litec Gbr, Toyoda Gosei Company Limited (Toyota Motor Corporation), Tridonic Optoelectronics GmbH
• Inventors: Starick, Detlef, Kempfert, Wofgang, Roth, Gundula, Tews, Walter, Tasch, Stefan, Pachler, Peter, Ota, Koichi, Hirano, Atsuo, Ota, Akihito
• Application Number:
  US12/659,025
• Publication Number:
  US 20100155761A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77344 Aluminosilicates
• CPC Class Codes: C09K 11/774 Borates
• CPC Class Codes: C09K 11/7795 Phosphates
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: H01L 2224/16145 the bodies being stacked
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/45139 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 : Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2933/0091 : Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/06 : within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/502 : 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
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A light emitting device includes a light emitting element comprising a nitride semiconductor and a phosphor that can absorb a part of light emitted from the light emitting element and can emit light of a wavelength different from that of the absorbed light. The phosphor comprises a silicate phosphor comprising three alkali earth metals.

Claims

1. A light emitting device, comprising:

a light emitting element comprising a nitride semciconductor; and

a phosphor that can absorb a part of light emitted from said light emitting element and can emit light of a wavelength different from that of said absorbed light,

wherein said phosphor comprises a silicate phosphor comprising three alkali earth metals.

2. The light emitting device according to claim 1, wherein said silicate phosphor comprises barium (Ba), calcium (Ca), and strontium (Sr).

3. The light emitting device according to claim 1, wherein said silicate phosphor comprises a divalent-europium-activated alkaline earth metal silicate represented by a formula:

(2-x-y)SrO.x(Ba,Ca)O.(1-a-b-c-d)SiO₂. aP₂O₅bAl₂O₃cB₂O₃dGeO₂;

yEu²⁺

where

0<

x<

1.6, 0.005<

y<

0.5, and 0<

a,b,c,and d <

0.5, and/or

a divalent-europium-activated alkaline earth metal silicate represented by a formula;

(2-x-y)BaO.x(Sr,Ca)O.(1-a-b-c-d)SiO₂.aP₂O₅bAl₂O₃cB₂O₃dGeO₂;

yEu²⁺

where

0.01<

x<

1.6, 0.005<

y<

0.5, and 0<

a,b,c, and d<

0.5.

4. The light emitting device according to claim 1, wherein said silicate phosphor emits a light with a half bandwidth up to 110 nm.

5. The light emitting device according to claim 1, wherein said light emitting device emits white light.

6. The light emitting device according to claim 1, wherein said light emitting element comprises a peak emission wavelength of 380 to 500 nm.

7. The light emitting device according to claim 1, wherein a half-value width of a wavelength emitted from said light emitting element is not more than 500 nm.

8. The light emitting device according of claim 1, wherein said nitride semiconductor comprises GaN-based semiconductor.

9. The light emitting device according to claim 1, wherein said phosphor further comprises a different phosphor for emitting a red light.

10. The light emitting device according to claim 9, wherein said different phosphor is selected from a group of an alkaline earth metal-magnesium-disilicate:

Eu²⁺, Mn²⁺ represented by a formula;

Me_(3-x-y)MgSi₂O₃;

xEu, yMn where 0.005<

x<

0.5, 0.005<

y<

0.5, and Me comprises Ba and/or Sr and/or Ca.