Light emitting device and light emitting device package

• US 8,710,535 B2
• Filed: 04/12/2013
• Issued: 04/29/2014
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Jo, Kyoung Woo, Kim, Sun Kyung, Choi, Woon Kyung
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): TAYLOR, EARL N
• Application Number:
  US13/862,267
• Publication Number:
  US 20130228813A1
• Time in Patent Office: 382 Days
• Field of Search: 257/98, 257/E33.067, 257/E33.068
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/00014 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 2924/01055 Cesium [Cs]
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• 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
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

Disclosed are a light emitting device, a method of manufacturing the same and a light emitting device package. The light emitting device of the embodiment includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer between the first and second conductive semiconductor layers; a fluorescent layer on the light emitting structure; and a light extracting structure on the fluorescent layer. The light extracting structure extracts light, which is generated in the light emitting structure and incident into an interfacial surface between the fluorescent layer and the light extracting structure, to an outside of the light emitting structure.

Claims

1. A light emitting device comprising:

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

a fluorescent layer on the light emitting structure;

a light extracting pattern on the fluorescent layer;

wherein the light extracting pattern is on a top surface of the fluorescent layer,

wherein the light extracting pattern partially exposes the top surface of the fluorescent layer, and

wherein at least one portion of the top surface of the fluorescent layer is higher than a top most surface of the light extracting pattern.

2. The light emitting device as claimed in claim 1, wherein the light extracting pattern diffracts light which is emitted through a spontaneous emission converted by the fluorescent layer incident into an interfacial surface between the fluorescent layer and the light extracting pattern.

3. The light emitting device as claimed in claim 2, wherein an emission distribution of light in the fluorescent layer is directed in a vertical direction rather than a lateral direction during the light is diffracted and extracted by the light extracting pattern.

4. The light emitting device as claimed in claim 1, wherein the light extracting pattern comprises at least one convex portion and at least one concave portion, and the top surface of the fluorescent layer is exposed through the at least one concave portion.

5. The light emitting device as claimed in claim 1, wherein the light extracting pattern comprises a periodic pattern, wherein the periodic pattern has a period of 50nm to 3000nm.

6. The light emitting device as claimed in claim 1, wherein the light extracting pattern comprises a non-periodic pattern.

7. The light emitting device as claimed in claim 1, wherein the fluorescent layer has a uniform thickness.

8. The light emitting device as claimed in claim 1, wherein the light extracting pattern comprises a material having a refractive index different from that of the fluorescent layer.

16. The light emitting device as claimed in claim 1, further comprising a first electrode on the light emitting structure, and a current blocking layer between the light emitting structure and the second electrode layer,

wherein the first electrode is not vertically overlapped with the current blocking layer.

17. The light emitting device as claimed in claim 1, wherein the top most surface of the fluorescent layer is higher than the top most surface of the light extracting pattern.

9. A light emitting device comprising:

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

a fluorescent layer on the light emitting structure;

a light extracting pattern on the fluorescent layer;

a second electrode layer under the light emitting structure;

a current blocking layer between the light emitting structure and the second electrode layer; and

a protection member below the light emitting structure,

wherein the second electrode layer includes at least one of an ohmic layer, a reflection layer, a junction layer, or a support substrate, and

wherein the protection member is formed circumferentially between the light emitting structure and the second electrode layer.

10. The light emitting device as claimed in claim 9, wherein at least a part of the protection member is overlapped with the light emitting structure in a vertical direction.

11. The light emitting device as claimed in claim 9, wherein the protection member comprises at least one of an electric insulative material, a material having lower electric conductivity than the reflection layer or the junction layer, or a material forming a Schottky connection with the second conductive semiconductor layer.

12. The light emitting device as claimed in claim 9, wherein the light extracting pattern is directly disposed on a top surface of the fluorescent layer, and

the light extracting pattern partially exposes the top surface of the fluorescent layer.

13. The light emitting device as claimed in claim 9, wherein the light extracting pattern diffracts light incident into an interfacial surface between the fluorescent layer and the light extracting pattern.

14. The light emitting device as claimed in claim 9, wherein the light extracting pattern comprises at least one convex portion and at least one concave portion, and the top surface of the fluorescent layer is exposed through the at least one concave portion.

15. The light emitting device as claimed in claim 9, wherein the light extracting pattern comprises a periodic or non-periodic pattern.

18. The light emitting device as claimed in claim 9, wherein a top surface of the fluorescent layer is higher than a top most surface of the light extracting pattern.

19. The light emitting device as claimed in claim 10, wherein a top most surface of the fluorescent layer is higher than the top most surface of the light extracting pattern.

20. The light emitting device as claimed in claim 9, further comprising a first electrode on the light emitting structure, wherein the first electrode is not vertically overlapped with the current blocking layer.