Green phosphor converted light emitting diode

• US 6,682,207 B2
• Filed: 06/22/2001
• Issued: 01/27/2004
• Est. Priority Date: 01/29/1999
• Status: Expired due to Term

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: Muller-Mach, Regina B., Trutna, William R. Jr., Muller, Gerd O., Weber, Andreas G., Cutler, Gregory M.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): WARD, JOHN A
• Application Number:
  US09/887,954
• Publication Number:
  US 20010036083A1
• Time in Patent Office: 949 Days
• Field of Search: 362/230, 362/231, 362/259, 362/293, 372/43, 372/50, 257/89, 257/93, 257/40, 257/88, 257/96, 313/503, 313/504, 313/505, 313/506, 313/501
• US Class Current: 362/293
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A light emitting device comprises a light emitting diode that emits primary light and a SrGa₂S₄:Eu²⁺ phosphor material capable of absorbing at least a portion of the primary light and emitting secondary light. The secondary light includes a wavelength longer than a wavelength of the primary light.

Claims

1. A light emitting device comprising:

a light emitting diode that emits primary light; and

a SrGa₂S₄;

Eu²⁺ phosphor material capable of absorbing at least a portion of said primary light and emitting secondary light including a wavelength longer than a wavelength of said primary light;

wherein the phosphor material is positioned such that at least a portion of the primary light is incident on the phosphor material prior to being incident on an optic.

2. The light emitting device of claim 1, wherein said light emitting diode is a laser diode.

3. The light emitting device of claim 1, wherein said secondary light includes green light.

4. The light emitting device of claim 1, wherein said light emitting diode is one of an array of light emitting diodes.

5. The light emitting device of claim 1, wherein said SrGa₂S₄:

Eu²⁺ phosphor material is spaced apart from said light emitting diode.

6. The light emitting device of claim 1, wherein said SrGa₂S₄:

Eu²⁺ phosphor material is included in a phosphor containing layer on which said primary light is incident.

7. The light emitting device of claim 1, wherein said primary light includes blue light.

8. A method of fabricating a light emitting device, the method comprising:

providing a light emitting diode that emits primary light; and

positioning a SrGa₂S₄;

Eu²⁺ phosphor material relative to said light emitting diode such that said phosphor material can absorbs at least a portion of said primary light and emits secondary light including a wavelength longer than a wavelength of said primary light;

wherein the phosphor material is positioned such that at least a portion of the primary light is incident on the phosphor material prior to being incident on an optic.

9. The method of claim 8, wherein said light emitting diode is a laser diode.

10. The method of claim 8, wherein said secondary light includes green light.

11. The method of claim 8, wherein said light emitting diode is one of an array of light emitting diodes.

12. The method of claim 8, further comprising spacing said SrGa₂S₄:

Eu²⁺ phosphor material apart from said light emitting diode.

13. The method of claim 8, wherein said SrGa₂S₄:

Eu²⁺ phosphor material is included in a phosphor containing layer on which said primary light is incident.

14. The method of claim 8, wherein said primary light includes blue light.