PLANARIZED LED WITH OPTICAL EXTRACTOR

• US 20100051970A1
• Filed: 11/15/2007
• Published: 03/04/2010
• Est. Priority Date: 11/17/2006
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Ouderkirk, Andrew J., Leatherdale, Catherine A.
• Application Number:
  US12/515,400
• Publication Number:
  US 20100051970A1
• Time in Patent Office: Days
• US Class Current: 257/88
• 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 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting article is disclosed and includes a light emitting diode having an n-layer or p-layer with a first refractive index value. A planarizing layer having a refractive index value equal to or greater than the first refractive index value is disposed on the n-layer or p-layer, and a patterned electrode is disposed on the n-layer or p-layer. An extractor having a light input surface is optically coupled to the planarizing layer.

Claims

1. A light emitting article comprising:

a light emitting diode comprising an n-layer or p-layer having a first refractive index value, a planarizing layer having a refractive index value equal to or greater than the first refractive index value and disposed on the n-layer or p-layer, and a patterned electrode disposed on the n-layer or p-layer; and

an extractor having a light input surface optically coupled to the planarizing layer forming a light emitting interface.

2. A light emitting article according to claim 1, wherein the planarizing layer and the patterned electrode form a coplanar surface.

3. A light emitting article according to claim 1, wherein the planarizing layer has a surface roughness of less than 20 nm.

4. A light emitting article according to claim 1, wherein the patterned electrode has an interdigitated pattern or spiral pattern.

5. A light emitting article according to claim 1, wherein at least a portion of the patterned electrode extends beyond the light emitting interface.

6. A light emitting article according to any of claims 1, further comprising a gap defined by the distance between the planarizing layer and the extractor, the gap being less than 100 nm.

7. A light emitting article according claim 1, further comprising an optically conducting bonding layer bonding the planarizing layer to the extractor.

8. A method of forming a light emitting article comprising:

providing a light emitting diode comprising an n-layer or p-layer having a first refractive index value, a planarizing layer having a refractive index value equal to or greater than the first refractive index value and disposed on the n-layer or p-layer, and a patterned electrode disposed on the n-layer or p-layer; and

optically coupling a light input surface of an extractor to the planarizing layer.

9. A method according to claim 8, wherein providing the light emitting diode further comprises forming the patterned electrode on the n-layer or p-layer, wherein the patterned electrode defines a plurality of voids.

10. A method according to claim 8, wherein providing the light emitting diode further comprises:

disposing the planarizing layer within the voids to form a filled patterned electrode; and

planarizing the filled patterned electrode to form a planarizing layer and patterned electrode coplanar surface.

11. A method according to claim 8, wherein the planarizing step forms a coplanar surface having a surface roughness of less than 20 nm.

12. A method according to claim 8, further comprising optically coupling a light input surface of an extractor to the planarizing layer and patterned electrode coplanar surface.

13. A method according to claim 8, wherein the optically coupling step comprises bonding the light input surface to the planarizing layer and patterned electrode coplanar surface with an optically conducting bonding layer.

14. An array of light emitting articles comprising:

a plurality of light emitting diodes, each light emitting diode comprising an n-layer or p-layer having a first refractive index value, a planarizing layer having a refractive index value equal to or greater than the first refractive index value and disposed on the n-layer or p-layer, and a patterned electrode disposed on the n-layer or p-layer; and

a plurality of extractors, each extractor having a light input surface optically coupled to the corresponding planarizing layer.

15. An array of light emitting articles according to claim 14, wherein at least selected planarizing layers and patterned electrodes form a coplanar surface.

16. A method of forming an array of light emitting articles comprising:

providing an array of light emitting diodes, wherein each light emitting diode comprises an n-layer or p-layer having a first refractive index value, a planarizing layer having a refractive index value equal to or greater than the first refractive index value and disposed on the n-layer or p-layer, and a patterned electrode disposed on the n-layer or p-layer; and

optically coupling an array of extractor light input surfaces to the array of light emitting diodes planarizing surfaces.

17. A method according to claim 16, wherein providing the array of light emitting diodes further comprises forming the patterned electrode on each n-layer or p-layer, wherein each patterned electrode defines a plurality of voids.

18. A method according to claim 17, wherein providing the array of light emitting diodes further comprises:

disposing the planarizing layer within the voids to form a plurality of filled patterned electrodes; and

planarizing each filled patterned electrode to form a planarizing layer and patterned electrode coplanar surface.

19. A method according to claim 18, wherein the planarizing step forms a plurality of coplanar surfaces having a surface roughness of less than 20 nm.

20. A method according to claim 16, wherein the providing step further comprises providing an array light emitting diodes in wafer form.

21. A method according to claim 18, further comprising singulating the array of light emitting articles to form a plurality of light emitting articles.

22. A method according to claim 18, wherein the optically coupling step comprises bonding the array of light emitting diodes to the array of extractor light input surfaces with an optically conducting bonding layer.