Illumination System Comprising a Radiation Source and a Fluorescent Material

• US 20070252513A1
• Filed: 06/29/2005
• Published: 11/01/2007
• Est. Priority Date: 07/05/2004
• Status: Abandoned Application

• Current Assignee: Philips Lumileds Lighting (Apollo Global Management, Inc.), Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Schmidt, Peter, Justel, Thomas, Schnick, Wolfgang, Stadler, Florian
• Application Number:
  US11/571,534
• Publication Number:
  US 20070252513A1
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C09K 11/7718 with alkaline earth metals
• CPC Class Codes: C09K 11/7738 with alkaline earth metals
• CPC Class Codes: C09K 11/7774 Aluminates

Abstract

The invention concerns an illumination system for generation of colored, especially yellow, amber or red light, comprising a radiation source and a fluorescent material comprising at least one phosphor capable of absorbing a part of light emitted by the radiation source and emitting light of wavelength different from that of the absorbed light; wherein said at least one phosphor is a yellow to red-emitting europium(II)-activated oxonitridoaluminosilicate of general formula EA_2-zSi_5-aAl_aN_8-aO_a:Eu_z wherein 0<a≦2 and 0<z≦0.2; EA is at least one earth alkaline metal chosen from the group of calcium, barium and strontium.

The invention is also concerned with a red, amber or yellow-emitting a europium(II)-activated oxonitridoaluminosilicate of general formula EA_2-zSi_5-aAl_aN_8-aO_a:Eu_z wherein 0<a≦2 and 0<z≦0.2; EA is at least one earth alkaline metal chosen from the group of calcium, barium and strontium.

Claims

1. Illumination system, comprising a radiation source and a fluorescent material comprising at least one phosphor capable of absorbing part of the light emitted by the radiation source and emitting light of a wavelength different from that of the absorbed light;

wherein said at least one phosphor is a europium(II)-activated oxonitridoaluminosilicate of the general formula EA_2-zSi_5-aAl_aN_8-aO_a;

Eu_z, wherein

0<

a≦

2 and 0<

z≦

0.2;

EA being at least one alkaline earth metal chosen from the group of calcium, barium, and strontium.

2. Illumination system according to claim 1, wherein the radiation source is a solid-state light-emitting diode.

3. Illumination system according to claim 1, for the generation of yellow, amber, or red light, wherein the radiation source is selected from the light-emitting diodes having an emission with a peak emission wavelength in the range of 400 to 495 nm.

4. Illumination system according to claim 3, wherein the fluorescent material comprises a second phosphor.

5. Illumination system according to claim 4, wherein the second phosphor is a red phosphor selected from the group Ca_1-x-ySr_xS:

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2; and

(Sr_1-x-yBa_xCa_y)₂Si₅N₈;

Eu_z, wherein 0≦

x≦

1, 0≦

y≦

1 and 0<

z≦

0.2.

6. Illumination system according to claim 4, wherein the second phosphor is a yellow to green phosphor selected from the group comprising (Ca_xSr_1-x-y)₂SiO₄:

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Sr_xBa_1-x-y)₂SiO₄;

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Sr_1-x-yBa_x)Ga₂S₄;

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Y_1-x-y-zGd_xLu_z)₃(Al_1-aGa_a)₅O₁₂;

Ce_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, 0≦

z≦

1, 0≦

a≦

0.5, ZnS;

Cu, CaS;

Ce,Cl, and SrSi₂N₂O₂;

Eu.

7. Illumination system according to claim 4, wherein the second phosphor is a blue phosphor selected from the group of BaMgAl_1o0₁₇:

Eu, Ba₅SiO₄(Cl,Br)₆;

Eu, CaLa₂S₄;

Ce, (Sr,Ba,Ca) ₅(PO₄)₃Cl;

Eu, and LaSi₃N₅;

Ce.

8. Illumination system according to claim 1, for the generation of yellow, amber, or red light, wherein the radiation source is selected from the light-emitting diodes having an emission with a peak emission wavelength in the UV range of 200 to 420 nm.

9. Illumination system according to claim 8, wherein the fluorescent material comprises a second phosphor.

10. Illumination system according to claim 8, wherein the second phosphor is a red phosphor selected from the group Ca_1-x-ySr_xS:

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2; and

(Sr_1-x-yBa_xCa_y)₂Si₅N₈;

Eu_z, wherein 0≦

x≦

1, 0≦

y≦

1 and 0<

z≦

0.2.

11. Illumination system according to claim 8, wherein the second phosphor is a yellow to green phosphor selected from the group comprising (Ca_xSr_1-x-y)₂SiO₄:

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Sr_xBa_1-x-y)₂SiO₄;

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Sr_1-x-yBa_x)Ga₂S₄;

Eu_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, (Y_1-x-y-zGd_xLu_z)₃(Al_1-aGa_a)₅O₁₂;

Ce_y, wherein 0≦

x≦

1 and 0<

y≦

0.2, 0≦

z≦

1, 0≦

a≦

0.5, ZnS;

Cu, CaS;

Ce,Cl, and SrSi₂N₂O₂;

Eu.

12. Illumination system according to claim 8, wherein the second phosphor is a blue phosphor selected from the group of BaMgAl₁₀0₁₇:

Eu, Ba₅SiO₄(Cl,Br)₆;

Eu, CaLa₂S₄;

Ce, (Sr,Ba,Ca) ₅(PO₄)₃Cl;

Eu, and LaSi₃N₅;

Ce.

15. Phosphor according to claim 12, wherein the phosphor has a coating selected from the group of fluorides and orthophosphates of the elements aluminum, scandium, yttrium, lanthanum gadolinium, and lutetium, the oxides of aluminum, yttrium, and lanthanum, and the nitride of aluminum.

13. Phosphor capable of absorbing part of the light emitted by the radiation source and emitting light of a wavelength different from that of the absorbed light;

wherein said phosphor is a europium(II)-activated oxonitridoaluminosilicate of the general formula EA_2-zSi_5-aAl_aN_8-aO_a;

Eu_z, wherein 0<

a≦

2 and 0<

z≦

0.2;

EA being at least one alkaline earth metal chosen from the group of calcium, barium, and strontium.

14. Phosphor according to claim 13, wherein said phosphor additionally comprises a co-activator selected from the group of ytterbium and samarium.