Green-light emitting phosphors and light sources using the same

• US 6,278,135 B1
• Filed: 08/31/1998
• Issued: 08/21/2001
• Est. Priority Date: 02/06/1998
• Status: Expired due to Term

• Current Assignee: Current Lighting Solutions, LLC (f/k/a GE Lighting Solutions, LLC) (American Industrial Partners)
• Original Assignee: General Electric Company
• Inventors: Srivastava, Alok Mani, Beers, William Winder
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): ANYA, IGWE U
• Application Number:
  US09/144,137
• Time in Patent Office: 1,086 Days
• Field of Search: 257/98, 257/97, 257/99, 257/89, 315/56, 313/487, 313/637, 250/582, 607/88, 606/9, 606/11
• US Class Current: 257/98
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: H01L 33/502 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
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A phosphor composition absorbs ultraviolet radiation and emits a green visible light. The phosphor composition comprises at least one of: Ba₂SiO₄:Eu²⁺; Ba₂MgSi₂O₇:Eu²⁺; Ba₂ZnSi₂O₇:Eu²⁺; BaAl₂O₄:Eu²⁺; SrAl₂O₄:Eu²⁺; and BaMg₂Al₁₆O₂₇:Eu²⁺,Mn²⁺. Further, when the green-light emitting phosphor is combined with appropriate red and blue phosphors in a phosphor conversion material blend, and the phosphor conversion material blend absorbs ultraviolet radiation, and emits a bright white light with high brightness and quality. The ultraviolet radiation source may comprise a semiconductor ultraviolet radiation source.

Claims

1. A light source comprising:

a light emitting diode which emits ultraviolet light; and

a phosphor composition that is capable of absorbing ultraviolet radiation and emitting visible light, the phosphor composition comprising at least one of;

Ba₂SiO₄;

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺, Ba₂ZnSi₂O₇;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

SrAl₂O₄;

Eu²⁺; and

BaMg₂Al₁₆O₂₇;

Eu²⁺.

2. The light source according to claim 1, wherein the Ba₂SiO₄:

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺, Ba₂ZnSi₂O₇;

Eu²⁺; and

BaAl₂O₄;

Eu²⁺ each further comprise Mn²⁺ as an additional activator.

3. The light source according to claim 1, wherein the phosphor composition is capable of emitting green light.

4. The light source according to claim 1, wherein Ba₂SiO₄:

Eu²⁺ emits a green light with a wavelength of about 505 nm;

Ba₂MgSi₂O₇;

Eu²⁺ emits a green light with a wavelength of about 500 nm;

Ba₂ZnSi₂O₇;

Eu²⁺ emits a green light with a wavelength of about 505 nm;

BaAl₂O₄;

Eu²⁺ emits a green light with a wavelength of about 505 nm;

SrAl₂O₄;

Eu²⁺ emits a green light with a wavelength of about 520 nm; and

BaMg₇Al₁₆O₂₇;

Eu²⁺,Mn²⁺ emits a green light with a wavelength of about 515 nm.

5. The light source according to claim 1, wherein the phosphor composition absorbs ultraviolet radiation with a wavelength in a range between about 330 un and about 400 rum.

6. The light source according to claim 1, wherein the phosphor composition absorbs ultraviolet radiation with a wavelength in a range between about 350 nm and about 400 nm.

7. The light source according to claim 1, wherein the phosphor composition absorbs ultraviolet radiation with a wavelength in a range between about 365 nm and about 375 nm.

8. The light source according to claim 1, wherein the phosphor composition absorbs ultraviolet radiation with a wavelength at about 370 nm.

9. The light source of claim 1, wherein the phosphor composition comprises Ba₂SiO₄:

Eu²⁺.

10. The light source of claim 1, wherein the phosphor composition comprises Ba₂MgSi₂O₇:

Eu²⁺.

11. The light source of claim 1, wherein the phosphor composition comprises Ba₂ZnSi₂O₇:

Eu²⁺.

12. The light source of claim 1, wherein the phosphor composition comprises BaAl₂O₄:

Eu²⁺.

13. The light source of claim 1, wherein the phosphor composition comprises SrAl₂O₄:

Eu²⁺.

14. The light source of claim 1, wherein the phosphor composition comprises BaMg₂Al₁₆O₂₇:

Eu²⁺.

15. A light emitting diode that is capable of absorbing ultraviolet radiation and emitting a green visible light, the light emitting diode comprising:

a semiconductor radiation source; and

a phosphor comprising at least one of Ba₂SiO₄;

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺, Ba₂ZnSi₂O₇;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

SrAl₂O₄;

Eu²⁺; and

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺.

16. The light emitting diode according to claim 15, wherein the Ba₂SiO₄:

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺;

Ba₂ZnSi₂O₇;

Eu²⁺; and

BaAl₂O₄;

Eu²⁺ each further comprises Mn²⁺ an additional activator.

17. A light emitting diode that is capable of absorbing ultraviolet radiation and absorbs emitting a green visible light, the light emitting diode comprising:

a semiconductor radiation source; and

a phosphor comprising at least one of;

Ba₂SiO₄;

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺;

Ba₂ZnSi₂O₇;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

SrAl₂O₄;

Eu²⁺; and

BaMg₂Al₁₆O₂₇;

Eu²⁺, Mn²⁺, wherein Ba₂SiO₄;

Eu² emits a green light with a wavelength about 505 nm;

Ba₂MgSi₂O₇;

Eu²⁺ emits a green light with a wavelength about 500 nm;

Ba₂ZnSi₂O₇;

Eu²⁺ emits a green light with a wavelength about 505 nm;

BaAl₂O₄;

Eu²⁺ emits a green light with a wavelength about 505 nm;

SrAl₂O₄;

Eu²⁺ emits a green light with a wavelength about 520 nm; and

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺ emits a green light with a wavelength about 515 nm.

18. The light emitting diode according to claim 17, wherein the phosphor absorbs ultraviolet radiation with a wavelength in a range between about 330 nm and about 400 nm.

19. The light emitting diode according to claim 17, wherein the phosphor absorbs ultraviolet radiation with a wavelength in a range between about 350 nm and 400 nm.

20. The light emitting diode according to claim 17, wherein the phosphor absorbs ultraviolet radiation with a wavelength in a range between about 365 nm and about 375 nm.

21. The light emitting diode according to claim 17, wherein the phosphor absorbs ultraviolet radiation with a wavelength at about 370 nm.

22. A light emitting diode that is capable of emitting a white visible light, the light emitting diode comprising:

a semiconductor radiation source; and

a phosphor conversion material blend composition comprising;

at least one red-light emitting phosphor;

at least one blue-light emitting phosphor; and

at least one green-light emitting phosphor selected from the group consisting of;

Ba₂SiO₄;

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺;

Ba₂ZnSi₂O₇;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

SrAl₂O₄;

Eu²⁺; and

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺.

23. The light emitting diode according to claim 22, wherein the Ba₂SiO₄:

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺;

Ba₂ZnSi₂O₇;

Eu²⁺; and

BaAl₂O₄;

Eu²⁺ each further comprise Mn²⁺ an additional activator.

24. A light emitting diode that is capable of absorbing ultraviolet radiation and emitting the ultraviolet radiation into a white visible light, the light emitting diode comprising:

a semiconductor radiation source; and

a phosphor conversion material blend composition comprising;

at least one red-light emitting phosphor;

at least one blue-light emitting phosphor; and

at least one green-light emitting phosphor selected from the group consisting of;

Ba₂SiO₄;

Eu²⁺;

Ba₂MgSi₂O₇;

Eu²⁺;

Ba₂ZnSi₂O₇;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

BaAl₂O₄;

Eu²⁺;

SrAl₂O₄;

Eu²⁺; and

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺, wherein Ba₂SiO₄;

Eu²⁺ emits a green light with a wavelength about 505 nm;

Ba₂MgSi₂O₇;

Eu²⁺ emits a green light with a wavelength about 500 nm;

Ba₂ZnSi₂O₇;

Eu²⁺ emits a green light with a wavelength about 505 nm;

BaAl₂O₄;

Eu²⁺ emits a green light with a wavelength about 505 nm;

SrAl₂O₄;

Eu²⁺ emits a green light with a wavelength about 520 nm; and

BaMg₂Al₁₆O₂₇;

Eu²⁺,Mn²⁺ emits a green light with a wavelength about 515 nm.

25. The light emitting diode according to claim 24, wherein the at least one green-light emitting phosphor absorbs ultraviolet radiation with a wavelength in a range between about 330 nm and about 400 nm.

26. The light emitting diode according to claim 24, wherein the at least one green-light emitting phosphor absorbs ultraviolet radiation with a wavelength in a range between about 350 nm and about 400 nm.

27. The light emitting diode according to claim 24, wherein the at least one green-light emitting phosphor absorbs ultraviolet radiation with a wavelength in a range between about 365 nm and about 375 nm.

28. The light emitting diode according to claim 24, wherein the at least one green-light emitting phosphor absorbs ultraviolet radiation with a wavelength at about 370 nm.