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

• US 8,748,927 B2
• Filed: 04/02/2013
• Issued: 06/10/2014
• Est. Priority Date: 04/23/2010
• 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): Dickey, Thomas L
• Assistant Examiner(s): Schoenholtz, Joseph
• Application Number:
  US13/855,135
• Publication Number:
  US 20130240938A1
• Time in Patent Office: 434 Days
• Field of Search: None
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Disclosed are a light emitting device, a light emitting device package, and a lighting system. The light emitting device includes an electrode layer, a current density adjusting pattern on the electrode layer, and a light emitting structure on the electrode layer and the current density adjusting pattern. The light emitting structure includes a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer. The first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion.

Claims

1. A light emitting device comprising:

an electrode layer;

a current density adjusting pattern on the electrode layer; and

a light emitting structure on the electrode layer and the current density adjusting pattern, the light emitting structure including a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer,

wherein the first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion, and

wherein the column pattern or the hole pattern forms an in-phase relationship with respect to the current density adjusting pattern.

2. The light emitting device of claim 1, wherein the light emitting structure includes a thickness less than about 2 μ

m.

4. The light emitting device of claim 1, wherein the current density adjusting pattern has a width different from a width of the column pattern or the hole pattern.

5. The light emitting device of claim 1, further comprising a reflective layer provided at a lateral side of the column pattern or the hole pattern.

6. The light emitting device of claim 1, wherein the thickness of the upper portion is greater than a thickness of the second conductive semiconductor layer.

7. The light emitting device of claim 1, wherein the thickness of the lower portion is in a range of about 500 nm to about 1000 nm.

8. The light emitting device of claim 1, wherein the thickness of the upper portion is λ

/n in which the λ and

the n represent a main wavelength of a light emitted from the active layer and a refractive index of the first conductive semiconductor layer, respectively.

9. The light emitting device of claim 1, wherein the light emitting structure has a thickness in a range of about 1 μ

m to about 2 μ

m.

10. The light emitting device of claim 1, wherein the current density adjusting pattern comprises a non-conductive material or a metallic material making non-ohmic contact with respect to the second conductive semiconductor layer.

11. The light emitting device of claim 1, wherein the electrode layer comprises a conductive support member, a reflective layer on the conductive support member, and an ohmic layer on the reflective layer.

19. The light emitting device of claim 1, wherein the column pattern or the hole pattern vertically overlaps with respective ones of the current density adjusting pattern.

3. A light emitting device comprising:

an electrode layer;

a current density adjusting pattern on the electrode layer; and

a light emitting structure on the electrode layer and the current density adjusting pattern, the light emitting structure including a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer,

wherein the first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion,

wherein the column pattern or the hole pattern forms an out-of-phase relationship with respect to the current density adjusting pattern.

20. The light emitting device of claim 3, further comprising a reflective layer provided at a lateral side of the column pattern or the hole pattern.

12. A light emitting device package comprising:

a body;

at least one lead electrode on the body; and

a light emitting device electrically connected to the lead electrode,

wherein the light emitting device comprises;

an electrode layer;

a current density adjusting pattern on the electrode layer; and

a light emitting structure on the electrode layer and the current density adjusting pattern, the light emitting structure including a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer,

wherein the first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion,

wherein the column pattern or the hole pattern forms an in-phase relationship with respect to the current density adjusting pattern.

13. The light emitting device package of claim 12, wherein the light emitting structure includes a thickness less than about 2 μ

m.

14. The light emitting device package of claim 12, wherein the thickness of the upper portion is greater than a thickness of the second conductive semiconductor layer.

15. The light emitting device package of claim 12, wherein the thickness of the upper portion is λ

/n in which the λ and

the n represent a main wavelength of a light emitted from the active layer and a refractive index of the first conductive semiconductor layer, respectively.

16. The emitting device package of claim 12, wherein the current density adjusting pattern comprises a non-conductive material or a metallic material making non-ohmic contact with respect to the second conductive semiconductor layer.

17. A lighting system comprising:

a board; and

a light emitting module comprising a light emitting device on the board,

wherein the light emitting device comprises;

an electrode layer;

a current density adjusting pattern on the electrode layer; and

a light emitting structure on the electrode layer and the current density adjusting pattern, the light emitting structure including a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer,

wherein the first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion,

wherein the column pattern or the hole pattern forms an out-of-phase relationship with respect to the current density adjusting pattern.

18. The lighting system of claim 17, further comprising at least one of a light guide member, a diffusion sheet, a light collection sheet, a brightness enhancement sheet, and a fluorescent sheet provided on a path of a light emitted from the light emitting module.