Light emitting device, light emitting device package, and lighting system

• US 8,969,893 B2
• Filed: 02/24/2011
• Issued: 03/03/2015
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Kim, Sun Kyung
• Primary Examiner(s): SHINGLETON, MICHAEL B
• Application Number:
  US13/033,795
• Publication Number:
  US 20110266518A1
• Time in Patent Office: 1,468 Days
• Field of Search: 257/98, 257/79, 257/95, 257/100, 257/E33.001, 362/311.02, 362/800
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

Provided are a light emitting device, a light emitting device package, and a lighting system. The light emitting device includes a light emitting structure, a non-periodic light extraction pattern, and a phosphor layer. The light emitting structure includes a first conductive type semiconductor layer, a second conductive type semiconductor layer over the first conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer. The non-periodic light extraction pattern is disposed over the light emitting structure. The phosphor layer is disposed over the non-periodic light extraction pattern. The phosphor layer fills at least one portion of the non-periodic light extraction pattern.

Claims

1. A light emitting device comprising:

a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer over the first conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer;

a light extraction pattern comprising a non-periodic pattern in the light emitting structure; and

a phosphor layer over the light extraction pattern,

wherein the phosphor layer comprises a first surface near the light emitting structure and a second surface facing an opposite side from the first surface, and the first surface includes a plurality of protrusion patterns corresponding to the light extraction pattern disposed in the light emitting structure,

wherein at least two protrusion patterns of the plurality of protrusion patterns have substantially different widths from each other, and

wherein the second surface is substantially flat and is farther from the light emitting structure than the first surface,

wherein the light extraction pattern is disposed in the first conductive type semiconductor layer,

wherein the light extraction pattern comprises a side surface substantially perpendicular to the second surface of the phosphor layer,

wherein the light extraction pattern comprises a bottom surface and a first and a second side surfaces substantially perpendicular,

wherein the bottom surface is parallel with an upper surface of the first conductive type semiconductor layer,

wherein the first side surface is parallel to the second side surface.

2. The light emitting device according to claim 1, wherein the light extraction pattern comprises a pseudorandom pattern.

3. The light emitting device according to claim 2, wherein the pseudorandom pattern comprises a hole or a column that is randomly disposed within a limited space.

4. The light emitting device according to claim 3, wherein the pseudorandom pattern has a nearest mean distance ranging from about 200 nm to about 3000 nm.

5. The light emitting device according to claim 1, wherein the light extraction pattern comprises only non-periodic circular patterns.

6. The light emitting device according to claim 5, wherein the non-periodic circular patterns comprise holes or columns on circumferences of concentric circles.

7. The light emitting device according to claim 1, wherein the light extraction pattern comprises a light extraction pattern having no translational symmetry.

15. The light emitting device according to claim 1, wherein an entire combined emitted light distribution from the phosphor layer is similar to an entire combined emitted light distribution from the light emitting structure.

16. The light emitting device according to claim 1, further comprising an electrode layer under the light emitting structure, wherein the electrode layer comprises a reflective layer, a conductive support substrate, and an adhesive layer disposed between the reflective layer and the conductive support substrate.

17. The light emitting device according to claim 16,

wherein the reflective layer includes at least one of Ag, Ni, Al, Pd, and Pt,

wherein the adhesive layer includes at least one of Ti, Au, Sn, Ni, Cr, and Cu, and

wherein the conductive support substrate includes a thickness ranging from about 30 μ

m to about 500 μ

m.

18. The light emitting device according to claim 16,

wherein the first conductive type semiconductor layer or a second conductive type semiconductor layer comprises an AlGaN layer,

wherein the active layer comprises an InGaN well layer and a GaN barrier layer or an InGaN well layer and an InGaN barrier layer.

8. A light emitting device comprising:

a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer over the first conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer;

a light extraction pattern comprising a non-periodic pattern in the light emitting structure; and

a phosphor layer over the light extraction pattern,

wherein the phosphor layer has a first surface facing the light emitting structure and a second surface facing an opposite side of the first surface, and the first surface of the phosphor layer includes a plurality of first protrusion patterns corresponding to the light extraction pattern disposed on the light emitting structure,

wherein the second surface is substantially flat,

wherein at least two protrusion patterns of the plurality of first protrusion patterns have substantially different widths from each other,

wherein the first conductive type semiconductor layer and the second conductive type semiconductor layer comprise at least one of an AlGaN layer and/or an InGaN layer, and

wherein the active layer comprises an InGaN well layer and a GaN barrier layer or an InGaN well layer and an InGaN barrier layer,

wherein the light extraction pattern is disposed in the first conductive type semiconductor layer,

wherein the light extraction pattern comprises a plurality of second protrusion patterns,

wherein a bottom width of one protrusion pattern of the plurality of second protrusion patterns is substantially the same as a top width of one protrusion pattern of the plurality of second protrusion patterns,

wherein the light extraction pattern comprises a bottom surface and a first and a second side surfaces substantially perpendicular,

wherein the bottom surface is parallel with an upper surface of the first conductive type semiconductor layer,

wherein the first side surface is parallel to the second side surface.

9. The light emitting device according to claim 8, wherein the light extraction pattern comprises a pseudorandom pattern.

10. The light emitting device according to claim 8, wherein the pseudorandom pattern comprises a hole or a column that is randomly disposed within a limited space.

11. The light emitting device according to claim 10, wherein the pseudorandom pattern has a nearest mean distance ranging from about 200 nm to about 3000 nm.

12. The light emitting device according to claim 8, wherein the light extraction pattern comprises only non-periodic circular patterns.

13. The light emitting device according to claim 12, wherein the non-periodic circular patterns comprise holes or columns on circumferences of concentric circles.

14. The light emitting device according to claim 8, wherein the light extraction pattern comprises a light extraction pattern having no translational symmetry.

19. The light emitting device according to claim 8, wherein the light extraction pattern is disposed in the first conductive type semiconductor layer, and

wherein the light extraction pattern comprises a side surface substantially perpendicular to the second surface of the phosphor layer.

20. A light emitting device comprising:

a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer over the first conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer;

a light extraction pattern comprising a non-periodic pattern in the light emitting structure; and

a phosphor layer over the light extraction pattern,

wherein the phosphor layer comprises a first surface near the light emitting structure and a second surface facing an opposite side from the first surface, and the first surface includes a first protrusion pattern, a second protrusion pattern, and a third protrusion pattern corresponding to the light extraction pattern disposed in the light emitting structure,

wherein the first protrusion pattern has substantially different widths from the second protrusion pattern and a first gap between the first protrusion pattern and the second protrusion pattern is different from a second gap between the second protrusion pattern and the third protrusion pattern,

wherein the second surface is substantially flat and is farther from the light emitting structure than the first surface,

wherein at least two of protrusion patterns have a top surface and bottom surface with a predetermined area,

wherein the light extraction pattern is disposed in the first conductive type semiconductor layer,

wherein the light extraction pattern comprises a bottom surface and a first and a second side surfaces substantially perpendicular,

wherein the bottom surface is parallel with an upper surface of the first conductive type semiconductor layer,

wherein the first side surface is parallel to the second side surface.