Red nitride phosphors

• US 8,906,263 B2
• Filed: 06/03/2011
• Issued: 12/09/2014
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Seibel, Harry A. II, Collins, Brian Thomas, Emerson, David Todd
• Primary Examiner(s): Koslow, Carol M
• Application Number:
  US13/152,863
• Publication Number:
  US 20120305958A1
• Time in Patent Office: 1,285 Days
• Field of Search: 252/301.4 F, 313/503, 257/98
• US Class Current: 252/301.4F
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch

Abstract

Provided according to embodiments of the invention are phosphor compositions that include Ca_1-x-ySr_xEu_yAlSiN₃, wherein x is in a range of 0.50 to 0.99 and y is less than 0.013. Also provided according to embodiments of the invention are phosphor compositions that include Ca_1-x-ySr_xEu_yAlSiN₃, wherein x is in a range of 0.70 to 0.99 and y is in a range of 0.001 and 0.025. Also provided are methods of making phosphors and light emitting devices that include a phosphor composition according to an embodiment of the invention.

Claims

1. A light emitting device, comprising:

a solid state lighting source; and

a phosphor composition that comprises Ca_1-x-ySr_xEu_yAlSiN₃, wherein x is in a range of 0.50 to 0.99 and y is less than 0.013, and

wherein the light emitting device has a CRI value of greater than 90.

2. The light emitting device of claim 1, comprising emission of a warm white light having a correlated color temperature between about 2700K and 5400K.

3. The light emitting device of claim 1, wherein the Sr to Eu ratio in the phosphor composition is in a range of 25 to 300.

4. The light emitting device of claim 1, wherein the phosphor composition is present in particulate form and at least 95% of the particles are elongated.

5. The light emitting device of claim 1, wherein the phosphor composition is present as particles having an average particle size in a range of 4 μ

m to 20 μ

m.

6. The light emitting device of claim 1, wherein the phosphor composition is present as a single crystal.

7. The light emitting device of claim 1, further comprising a green and/or yellow phosphor.

8. The light emitting device of claim 1, wherein the phosphor composition comprises at least 1% by weight of silicon aluminum oxynitride.

9. A light emitting device, comprising:

a solid state lighting source; and

a phosphor composition that comprises Ca_1-x-ySr_xEu_yAlSiN₃, wherein x is in a range of 0.70 to 0.99 and y is in a range of 0.001 to 0.025, and

wherein the light emitting device has a CRI value of greater than 90.

10. The light emitting device of claim 9, comprising emission of a warm white light having a correlated color temperature between about 2700K and 5400K.

11. The light emitting device of claim 9, wherein the Sr to Eu ratio in the phosphor composition is in a range of 25 to 300.

12. The light emitting device of claim 9, wherein the phosphor composition is present in particulate form and at least 95% of the particles are elongated.

13. The light emitting device of claim 9, wherein the phosphor composition is present as particles having an average particle size in a range of 4 μ

m to 20 μ

m.

14. The light emitting device of claim 9, wherein the phosphor composition is present as a single crystal.

15. The light emitting device of claim 9, further comprising a green and/or yellow phosphor.

16. The light emitting device of claim 9, wherein the phosphor composition comprises at least 1% by weight of silicon aluminum oxynitride.