Light emitting devices including wavelength converting material

• US 7,781,779 B2
• Filed: 05/05/2008
• Issued: 08/24/2010
• 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.
• Primary Examiner(s): Soward; Ida M
• Application Number:
  US12/115,497
• Publication Number:
  US 20090040745A1
• Time in Patent Office: 841 Days
• Field of Search: 257/13, 257/79, 257/91, 257 94- 95, 257/98, 257/E33.001, 257/E33.067, 257102-103
• US Class Current: 257/79
• 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 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;

a first wavelength converting material region disposed on at least a portion of the top emission surface and a second wavelength converting material region disposed on at least a portion of the emission surface, wherein the first wavelength converting material is configured to emit light at a different frequency than the second wavelength converting material.

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

3. The light emitting device of claim 1, wherein the light emitting device is configured to emit white, green, blue, red, amber, cyan, yellow, UV and IR light.

4. The light emitting device of claim 1, wherein greater than 50% of the emitted light emerges from the light emitting device via the top emission surface.

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.

6. The light emitting device of claim 1, wherein greater than 90% of the emitted light emerges from the light emitting device via the top emission surface.

7. 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 first or second wavelength converting material.

8. 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 first or second wavelength converting material.

9. 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 first or second wavelength converting material.

10. The light emitting device of claim 1, wherein the first wavelength converting material region is separated from the second wavelength converting material region by a distance.

11. The light emitting device of claim 1, wherein the first wavelength converting material region and the second wavelength converting material region are arranged in a striped pattern.

12. The light emitting device of claim 1, wherein the wavelength converting material does not cover the entire emission surface.

13. The light emitting device of claim 1, wherein the light emitted from the first wavelength converting material region mixes with light emitted from the second wavelength converting material region.

14. The light emitting device of claim 1, wherein a thickness of the first wavelength converting material region and the second wavelength converting material region is between 100 nm and 100 microns.

15. The light emitting device of claim 1, wherein a length or width of the first wavelength converting material region and the second wavelength converting material region is between 1 micron and 100 microns.

16. The light emitting device of claim 1, wherein sidewalls of the multi-layer stack of material are substantially devoid of the wavelength converting material.

17. The light emitting device of claim 1, wherein the first and second wavelength converting materials are disposed according to a predetermined pattern.

18. The light emitting device of claim 17, wherein the predetermined pattern is configured to produce a desired color point.

19. The light emitting device of claim 1, further comprising a plurality of recesses formed in the top emission surface.

20. The light emitting device of claim 19, wherein the recesses are formed according to a pattern.

21. The light emitting device of claim 19, wherein the wavelength converting material is disposed only in the recesses in the top emission surface.

22. The light emitting device of claim 19, wherein the top emission surface is a top surface of an n-type layer.

23. The light emitting device of claim 19, wherein the recesses are holes.

24. The light emitting device of claim 23, wherein the holes have a cross-sectional dimension of less than 1 micron.

25. The light emitting device of claim 1, wherein at least one of the first and second wavelength converting materials are disposed according to a pattern.

26. The light emitting device of claim 25, wherein the pattern comprises a plurality of discrete features.

27. The light emitting device of claim 25, wherein the pattern comprises a plurality of stripes.

28. The light emitting device of claim 25, wherein the pattern is pre-determined.

29. The light emitting device of claim 25, wherein the pattern is configured to produce a desired color point.

30. The light emitting device of claim 29, wherein the pattern is configured to produce a desired color point by adjusting a ratio of size of the first wavelength converting material region in relation to distance between the first wavelength material region and the second wavelength converting material region.

31. The light emitting device of claim 25, wherein the first wavelength converting material and the second wavelength converting material are disposed according to a pattern.

32. The light emitting device of claim 31, wherein the pattern covers greater than 50% of the emission surface area.

33. The light emitting device of claim 31, wherein the pattern covers between 25% and 75% of the emission surface area.