LIGHT EMITTING DEVICES INCLUDING WAVELENGTH CONVERTING MATERIAL

• US 20110012156A1
• Filed: 07/21/2010
• Published: 01/20/2011
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Original Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Inventors: Nemchuk, Nikolay I.
• Granted Patent: US 8,217,402 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material

Abstract

Light-emitting devices and associated methods are provided. The light emitting devices can have a wavelength converting material-coated emission surface.

Claims

1. A light emitting device comprising:

a multi-layer stack of material including a n-doped region, an p-doped region and a light generating region disposed between the n-doped and p-doped regions, wherein at least a portion of the light generated from the light generating region emerges from the light emitting device via a top emission surface of the multi-layer stack of materials; and

a wavelength converting material layer disposed according to a pattern on the top emission surface of the multi-layer stack of material, wherein sidewalls of the multi-layer stack of material are substantially devoid of the wavelength converting material.

2. The light emitting device of claim 1, wherein the wavelength converting material is phosphor.

5. The light emitting device of claim 1, wherein greater than 75% of the emitted light emerges from the light emitting device via the top emission surface.

7. The light emitting device of claim 1, wherein the pattern comprises a plurality of discrete features.

8. The light emitting device of claim 1, wherein the pattern comprises a plurality of stripes.

9. The light emitting device of claim 1, wherein greater than 50% of light emitted at a first wavelength is converted to a desired second wavelength by the wavelength converting material.

10. The light emitting device of claim 1, wherein greater than 75% of light emitted at a first wavelength is converted to a desired second wavelength by the wavelength converting material.

11. The light emitting device of claim 1, wherein greater than 90% of light emitted at a first wavelength is converted to a desired second wavelength by the wavelength converting material.

12. The light emitting device of claim 1, wherein the pattern is pre-determined.

3-4. -4. (canceled)

6. (canceled)

13. A method of controlling color point of a wafer, comprising the steps of:

providing a wafer configured for emitting light;

determining a desired color point of light emitted by said wafer;

determining the applied thickness and/or pattern of a wavelength converting material to achieve said desired color point; and

forming a layer of wavelength converting material having the determined thickness and/or pattern on a top surface of the wafer.

14. The method of claim 13, wherein the wavelength converting material is in a pre-determined pattern.

15. The method of claim 14, wherein said predetermined pattern is designed to convert emitted light having a first wavelength to a desired second wavelength.

16. A method of forming a light emitting device, comprising the steps of:

providing a multi-layer stack of material;

disposing a wavelength converting material on a top surface of the multi-layer stack of material; and

dicing the multi-layer stack of material into a plurality of mesas.

17. The method of claim 16, further comprising the step of testing at least one of the plurality of mesas for a desired color point.

18. The method of claim 16, wherein the step of disposing the wavelength converting material on the top surface of the multi-layer stack of material further includes disposing said wavelength converting material according to a predetermined pattern.

19-22. -22. (canceled)

23. A light emitting device comprising:

a multi-layer stack of material including a n-doped region, an p-doped region and a light generating region disposed between the n-doped and p-doped regions, wherein at least a portion of the light generated from the light generating region emerges from the light emitting device via a top emission surface of the multi-layer stack of materials, wherein a plurality of recesses are formed in the top emission surface; and

a wavelength converting material layer disposed in the recesses in the top emission surface.

24. The light emitting device of claim 23, wherein the recesses are formed according to a pattern.

25. The light emitting device of claim 23, wherein the recesses are holes.

26. The light emitting device of claim 23, wherein the holes have dimensions of less than 1 micron.

27. The light emitting device of claim 23, wherein the wavelength converting material layer is disposed only in the recesses in the top emission surface.