Luminous substance for a light source and light source associates therewith

• US 6,669,866 B1
• Filed: 03/15/2001
• Issued: 12/30/2003
• Est. Priority Date: 07/23/1999
• Status: Expired due to Term

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG), Patent-Treuhand-Gesellschaft Fuer Elektrische Gluehlampen MbH (Siemens AG)
• Inventors: Debray, Alexandra, Zwaschka, Franz, Ellens, Andries, Waitl, Guenther, Kummer, Franz
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US09/787,208
• Time in Patent Office: 1,020 Days
• Field of Search: 252/301.4 R, 313/485, 257/98
• US Class Current: 252/301.40R
• CPC Class Codes: C09K 11/7715 containing cerium
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7774 Aluminates
• 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: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

Abstract

A phosphor for light sources, the emission from which lies in the short-wave optical spectral region, as a garnet structure A₃B₅O₁₂. It is activated with Ce, the second component B representing at least one of the elements Al and Ga, and the first component A is terbium or terbium together with at least one of the elements Y, Gd, La and/or Lu.

In a preferred embodiment, a phosphor having a garnet of structure (Tb_1−x−yRE_xCe_y)₃(Al,Ga)₅O₁₂,

where

RE=Y, Gd, La and/or Lu;

0≦x≦0.5−y;

0<y<0.1 is used.

Claims

1. A light source comprising:

a radiation source having an emission from 420 to 490 nm and a phosphor having a garnet structure as represented by A₃B₅O₁₂;

Ce wherein A is terbium or terbium together with at least one of the elements Y, Gd, La, and/or Lu and B is at least one of the elements Al and Ga, the phosphor converting at least a part of the emission from the radiation source into a longer-wave radiation.

2. The light source of claim 1 wherein A is solely or predominately terbium.

3. The light source of claim 1 wherein the radiation source has an emission from 430 to 470 nm.

4. The light source of claim 2 wherein the radiation source has an emission from 430 to 470 nm.

5. The light source of claim 1 wherein the radiation source is a light-emitting diode.

6. The light source of claim 2 wherein the radiation source is a light-emitting diode.

7. The light source of claim 1 wherein B additionally contains In.

8. The light source of claim 6 wherein the light-emitting diode is based on Ga(In)N.

9. The light source of claim 1 wherein the phosphor contains from 0.03 to less than 3 moles of terbium per mole of phosphor.

10. The light source of claim 1 wherein the light-emitting diode is based on Ga(In)N.

12. The light source of claim 4 wherein x is in the range 0.25≦

x≦

0.5−

y.

28. The white light source of claim 5 wherein the light-emitting diode is based on Ga(In)N.

11. A light source comprising:

a radiation source having an emission from 420 to 490 nm and a phosphor for converting at least a portion of the emission from the radiation source into a longer-wave radiation, the phosphor having a garnet structure represented by

13. The light source of claim 11 wherein y is in the range 0.02<

y<

0.06.

14. The light source of claim 11 wherein the radiation source has an emission from 430 to 470 nm.

15. The light source of claim 11 wherein the radiation source is a light-emitting diode.

16. The light source of claims 11 wherein x is in the range 0.25≦

x≦

0.5−

y and y is in the range 0.02<

y<

0.06.

17. The light source of claim 11 wherein the light source has a color temperature of below 5000 K.

18. The light source of claim 11 wherein the light source has a color temperature of 4500 K.

19. A white light source comprising:

a light-emitting diode and a phosphor, the light-emitting diode having an emission from 420 to 490 nm, the phosphor having a garnet structure represented by A₃B₅O₁₂;

Ce wherein A is terbium or terbium together with at least one of the elements Y, Gd, La, and/or Lu and B is at least one of the elements Al and Ga, the phosphor converting a part of the emission from the light-emitting diode into a longer-wave radiation, the remaining emission from the light-emitting diode and the longer-wave radiation from the phosphor forming white light.

20. The white light source of claim 19 wherein the light-emitting diode is based on Ga(In)N.

21. The white light source of claim 19 wherein the phosphor contains from 0.03 to less than 3 moles of terbium per mole of phosphor.

22. A white light source comprising:

a light-emitting diode and a phosphor, the light-emitting diode having an emission from 420 to 490 nm, the phosphor converting a part of the emission from the light-emitting diode into a longer-wave radiation, the remaining emission from the light-emitting diode and the longer-wave radiation from the phosphor forming white light, the phosphor having a garnet structure represented by

23. The white light source of claim 22 wherein x is in the range 0.25<

x<

0.5−

y.

24. The white light source of claim 22 wherein y is in the range 0.02<

y<

0.06.

25. The white light source of claim 23 wherein y is in the range 0.02<

y<

0.06.

26. The white light source of claim 22 wherein the light source has a color temperature of below 5000 K.

27. The white light source of claim 22 wherein the light source has a color temperature of 4500 K.

29. A light source comprising:

a radiation source having an emission from 420 to 490 nm and a phosphor for converting at least a portion of the emission from the radiation source into a longer-wave radiation, the phosphor having a garnet structure represented by

30. The light source of claim 29 wherein x is 0.01.

31. The light source of claim 29 wherein y is in the range 0.01≦

y≦

0.05.

32. The light source of claim 30 wherein y is in the range 0.01<

y<

0.05.

33. The light source of claim 30 wherein the phosphor has a garnet structure represented by (Y_0.50, Gd_0.45Tb_0.01Ce_0.04)₃Al₅O₁₂.