Highly saturated red-emitting Mn (IV) activated phosphors and method of fabricating the same

• US 20080061674A1
• Filed: 11/07/2006
• Published: 03/13/2008
• Est. Priority Date: 09/12/2006
• Status: Active Grant

• Current Assignee: National Chiao Tung University (Government of The Republic of China)
• Original Assignee: National Chiao Tung University (Government of The Republic of China)
• Inventors: Chen, Teng-ming, Luo, Juih-Tzer
• Granted Patent: US 7,846,350 B2
• Time in Patent Office: Days
• US Class Current: 313/485
• CPC Class Codes: C09K 11/643 with alkaline earth metals
• CPC Class Codes: C09K 11/661 Chalcogenides
• CPC Class Codes: C09K 11/663 with alkaline earth metals
• CPC Class Codes: C09K 11/671 Chalcogenides
• CPC Class Codes: C09K 11/672 with zinc or cadmium
• CPC Class Codes: C09K 11/7701 Chalogenides
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

The present invention provides a light emitting device comprising a semiconductor light source emitting radiation at about 250˜500 nm; and a phosphor composition radiationally coupled to the semiconductor light source, wherein the phosphor composition is selected from the group consisting of Mg₁₄(Ge_(5-a)Mn_a)O₂₄, Sr(Ge_(4-b)Mn_b)O₉, Mg₂(Ti_(1-c)Mn_c)O₄, Zn₂(Ti_(1-d)Mn_d)O₄, SrMg(Al_(10-e)Mn_e)O₁₇, and Y₃(Ga_(5-f)Mn_f)O₁₂.

Claims

1. A light emitting device comprising a semiconductor light source emitting radiation at about 250 to 500 nm;

and a phosphor composition radiationally coupled to the semiconductor light source, wherein the phosphor composition is selected from the group consisting of Mg₁₄Ge₅O₂₄;

Mn⁴⁺, SrGe₄O₉;

Mn⁴⁺, Mg₂TiO₄;

Mn⁴⁺, Zn₂TiO₄;

Mn⁴⁺, SrMgAl₁₀O₁₇;

Mn⁴⁺, and Y₃Ga₅O₁₂;

Mn⁴⁺.

2. The light emitting device as described in claim 1, wherein the light source is a light emitting diode.

3. The light emitting device as described in claim 2, wherein the light emitting diode is a semiconductor comprising nitride.

4. The light emitting device as described in claim 1, wherein the light source is an organic light emitting device.

5. The light emitting device as described in claim 1, wherein the phosphor composition is coated on surface of the light source.

6. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Ge in Mg₁₄Ge₅O₂₄:

Mn⁴⁺ phosphor composition is 0.05˜

1 mol %.

7. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Ge in SrGe₄O₉:

Mn⁴⁺ phosphor composition is 0.25˜

2 mol %.

8. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Ti in Mg₂TiO₄:

Mn⁴⁺ phosphor composition is 0.05˜

2 mol %.

9. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Ti in Zn₂TiO₄:

Mn⁴⁺ phosphor composition is 0.05˜

2 mol %.

10. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Al in SrMgAl₁₀O₁₇:

Mn⁴⁺ phosphor composition is 0.05˜

1.5 mol %.

11. The light emitting device as described in claim 1, wherein the ratio that Mn substitutes Ga in Y₃Ga₅O₁₂:

Mn⁴⁺ phosphor composition is 0.05˜

1.5 mol %.

12. The light emitting device as described in claim 1, wherein the phosphor composition is excited by light from the semiconductor light source and emits light with C.I.E. chromaticity coordinate value of x ranging from 0.63 to 0.73 and y ranging from 0.26 to 0.34.

13. The light emitting device as described in claim 1, wherein the phosphor composition is excited by light from the semiconductor light source and emits light with wavelength of 600 to 680 nm.

14. A method of producing phosphor composition used in the light emitting device as described in claim 1, which is conducted by solid state synthesis at 1000˜

1600°

C.

15. The method as described in claim 14, wherein the reaction time is 6˜

10 hours.

16. The method as described in claim 14, wherein Mg₂TiO₄:

Mn⁴⁺ and Zn₂TiO₄;

Mn⁴⁺ phosphor composition are further sintered at 490˜

590°

C. under oxygen.

17. The method as described in claim 16, wherein the reaction time for sintering is 14˜

18 hours.