Feedback and coupling structures and methods

• US 6,911,674 B2
• Filed: 04/16/2003
• Issued: 06/28/2005
• Est. Priority Date: 04/16/2003
• Status: Expired due to Fees

• Current Assignee: MT Technology Enterprises, LLC
• Original Assignee: Zeolux Corporation
• Inventors: Evans, Allan Keneth
• Primary Examiner(s): Zarabian, Amir
• Assistant Examiner(s): Soward, Ida M.
• Application Number:
  US10/414,567
• Publication Number:
  US 20040206965A1
• Time in Patent Office: 804 Days
• Field of Search: 257 79- 80, 257/83, 257/88, 257431-432, 257/918
• US Class Current: 257/83
• CPC Class Codes: H01S 5/0424 lateral current injection
• CPC Class Codes: H01S 5/1215 Multiplicity of periods
• CPC Class Codes: H01S 5/187 using Bragg reflection
• CPC Class Codes: H01S 5/36 comprising organic materials
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: Y10S 257/918 Light emitting regenerative switching device, e.g. light emitting scr arrays, circuitry

Abstract

A light emitting device may include a light emitting layer such as an organic semiconductor material, one or more feedback structures, and a coupling structure. The one or more feedback structures may cause light emitted by the light emitting layer to be fed back through it along an axis in the plane of the device, thereby promoting the stimulated emission of light in the light emitting layer. The coupling structure couples some fraction of the feedback light out of the device. The coupled light may be emitted along an axis substantially normal to the plane of the device or at predetermined angles. The coupling and feedback structures may have a corrugated structure, a continuous variation of refractive index along an axis in the device plane, a period refractive index, or any combination thereof. The coupling and feedback structures may be separate, share common portion or combined together.

Claims

1. A light emitting diode device comprising:

a light emitting diode; and

a vertical coupling structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the light emitting diode includes a high index of refraction area sandwich between low index refraction areas.

2. The device of claim 1, wherein the output light propagates substantially normal to a plane substantially parallel to the light emitting diode.

3. The device of claim 1, wherein the output light propagates at ±

θ

°

to a normal to a plane substantially parallel to the light emitting diode.

4. The device of claim 1, wherein the vertical coupling structure is corrugated.

5. The device of claim 1, wherein the vertical coupling structure has an oscillating refractive index along a plane substantially parallel to the light emitting diode.

6. The device of claim 1, wherein the vertical coupling structure has a continuous variation in refractive index.

7. The device of claim 1, wherein the vertical coupling structure has a discontinuous variation in refractive index.

8. The device of claim 1, wherein the vertical coupling structure is periodic.

9. The device of claim 1, wherein the vertical coupling structure includes a first dielectric material and a second dielectric material.

10. The device of claim 1, further comprising a light feedback structure.

11. The device of claim 10, wherein the light feedback structure is corrugated.

15. The device of claim 10, wherein the light feedback structure is periodic.

16. The device of claim 1, wherein the vertical coupling structure includes part of a light feedback structure.

17. The device of claim 1, wherein the vertical coupling structure includes a light feedback structure.

18. The device of claim 1, wherein the high index of refraction area includes a light emitting material.

19. The device of claim 1, wherein the light emitting diode includes a light emitting material, the light emitting material being one of:

an organic semiconductor material;

a combination of organic and inorganic semiconductor materials;

or

an organometallic semiconductor material;

or

an inorganic semiconductor material.

12. A light emitting diode device comprising:

a light emitting diode;

a vertical coupling structure; and

a light feedback structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the light feedback structure has an oscillating refractive index along a plane substantially parallel to the light emitting diode.

13. A light emitting diode device comprising:

a light emitting diode;

a vertical coupling structure; and

a light feedback structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the light feedback structure has a continuous variation in refractive index.

14. A light emitting diode device comprising:

a light emitting diode;

a vertical coupling structure; and

a light feedback structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the light feedback structure has a discontinuous variation in refractive index.

20. A light emitting diode device comprising;

a light emitting diode; and

a vertical coupling structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the vertical coupling structure has an oscillating refractive index along a plane substantially parallel to the light emitting diode.

21. The device of claim 20, wherein the output light propagates substantially normal to a plane substantially parallel to the light emitting diode.

22. The device of claim 20, wherein the output light propagates at ±

θ

°

to a normal to a plane substantially parallel to the light emitting diode.

23. The device of claim 20, wherein the vertical coupling structure is corrugated.

24. The device of claim 20, wherein the vertical coupling structure is periodic.

25. The device of claim 20, wherein the vertical coupling structure includes a first dielectric material and a second dielectric material.

26. The device of claim 20, further comprising a light feedback structure.

27. The device of claim 26, wherein the light feedback structure is corrugated.

28. The device of claim 26, wherein the light feedback structure is periodic.

29. The device of claim 20, wherein the vertical coupling structure includes part of a light feedback structure.

30. The device of claim 20, wherein the vertical coupling structure includes a light feedback structure.

31. The device of claim 20, wherein the light emitting diode includes a light emitting material, the light emitting material being one of:

an organic semiconductor material;

a combination of organic and inorganic semiconductor materials;

or

an organometallic semiconductor material;

or

an inorganic semiconductor material.

32. A light emitting diode device comprising:

a light emitting diode; and

a vertical coupling structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the vertical coupling structure has a continuous variation in refractive index.

33. The device of claim 32, wherein the output light propagates substantially normal to a plane substantially parallel to the light emitting diode.

34. The device of claim 32, wherein the output light propagates at ±

θ

°

to a normal to a plane substantially parallel to the light emitting diode.

35. The device of claim 32, wherein the vertical coupling structure is corrugated.

36. The device of claim 32, wherein the vertical coupling structure is periodic.

37. The device of claim 32, wherein the vertical coupling structure includes a first dielectric material and a second dielectric material.

38. The device of claim 32, further comprising a light feedback structure.

39. The device of claim 38, wherein the light feedback structure is corrugated.

40. The device of claim 39, wherein the light feedback structure is periodic.

41. The device of claim 32, wherein the vertical coupling structure includes part of a light feedback structure.

42. The device of claim 32, wherein the vertical coupling structure includes a light feedback structure.

43. The device of claim 32, wherein the light emitting diode includes a light emitting material, the light emitting material being one of:

an organic semiconductor material;

a combination of organic and inorganic semiconductor materials;

or

an organometallic semiconductor material;

or

an inorganic semiconductor material.

44. A light emitting diode device comprising:

a light emitting diode; and

a vertical coupling structure,

wherein the vertical coupling structure changes a propagation direction of a portion of a substantially horizontal stimulated light emission within the light emitting diode such that the portion of the substantially horizontal stimulated light emission exits the light emitting diode as output light, and

wherein the vertical coupling structure has a discontinuous variation in refractive index.

45. The device of claim 44, wherein the output light propagates substantially normal to a plane substantially parallel to the light emitting diode.

46. The device of claim 45, wherein the output light propagates at ±

θ

°

to a normal to a plane substantially parallel to the light emitting diode.

47. The device of claim 44, wherein the vertical coupling structure is corrugated.

48. The device of claim 44, wherein the vertical coupling structure is periodic.

49. The device of claim 44, wherein the vertical coupling structure includes a first dielectric material and a second dielectric material.

50. The device of claim 44, further comprising a light feedback structure.

51. The device of claim 50, wherein the light feedback structure is corrugated.

52. The device of claim 50, wherein the light feedback structure is periodic.

53. The device of claim 44, wherein the vertical coupling structure includes part of a light feedback structure.

54. The device of claim 44, wherein the vertical coupling structure includes a light feedback structure.

55. The device of claim 44, wherein the light emitting diode includes a light emitting material, the light emitting material being one of:

an organic semiconductor material;

a combination of organic and inorganic semiconductor materials;

or

an organometallic semiconductor material;

or

an inorganic semiconductor material.