Light-emitting diode, light-emitting diode package, and lighting system including same

• US 10,199,534 B2
• Filed: 03/11/2016
• Issued: 02/05/2019
• Est. Priority Date: 03/11/2015
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Kang, Hyun Oh
• Primary Examiner(s): Gumedzoe, Peniel M
• Application Number:
  US15/557,019
• Publication Number:
  US 20180062028A1
• Time in Patent Office: 1,061 Days
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/235 Details of bases or caps, i.e. the parts that connect the light source to a fitting; Arrangement of components within bases or caps F21K9/238 takes precedence
• CPC Class Codes: F21K 9/237 Details of housings or cases, i.e. the parts between the light-generating element and the bases; Arrangement of components within housings or cases F21K9/238 takes precedence
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 29/80 with pins or wires
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

A light emitting diode according to an embodiment includes: a substrate; a first conductive semiconductor layer on the substrate; an active layer on the first conductive semiconductor layer; and a light emitting structure including a second conductive semiconductor layer on the active layer, wherein the active layer includes at least one quantum well layer and at least one quantum barrier layer, and each of the quantum well layers includes a plurality of well layers having different indium composition ratios, thereby improving internal quantum efficiency.

Claims

1. A light emitting diode comprising:

a substrate;

a first conductive semiconductor layer on the substrate;

an active layer on the first conductive semiconductor layer; and

a light emitting structure, including a second conductive semiconductor layer on the active layer, wherein the active layer comprises at least one quantum well layer and at least one quantum barrier layer, wherein the at least one quantum well layer includes a plurality of well layers having different indium composition ratios and a plurality of protrusion parts having different indium composition ratios, wherein one of the plurality of well layers is disposed at a center portion of the at least one quantum well layer and has the highest indium composition ratio in the at least one quantum well layer, wherein each of the plurality of protrusion parts is disposed between the plurality of well layers, wherein the plurality of protrusion parts has a lower indium composition ratio than that of the one of the plurality of well layers, wherein a band-gap energy of the plurality of protrusion parts is smaller than that of the at least one quantum barrier layer, wherein the plurality of protrusion parts are a region of a band-gap energy of the at least one quantum well layer.

2. The light emitting diode of claim 1, wherein the plurality of well layers comprises a first well layer, a second well layer having a different indium composition ratio from that of the first well layer on the first well layer, and

wherein the plurality of protrusion parts comprises a first protrusion part between the first well layer and the second well layer.

3. The light emitting diode of claim 2, wherein an indium composition ratio of the first well layer is lower than that of the second well layer and an indium composition ratio of the first protrusion part is lower than that of the second well layer.

4. The light emitting diode of claim 2, wherein band-gap energy of the first well layer is greater than that of the second well layer, and band-gap energy of the first protrusion part is greater than that of the second well layer.

5. The light emitting diode of claim 2, wherein the plurality of well layers comprises a third well layer on the second well layer, and

wherein the plurality of protrusion parts comprises a second protrusion part between the second well layer and the third well layer,

wherein the third well layer is disposed at the center portion of the quantum well layer.

6. The light emitting diode of claim 5, wherein the indium composition ratio of the second well layer is lower than that of the third well layer, and an indium composition ratio of the second protrusion part is lower than that of the third well layer.

7. The light emitting diode of claim 5, wherein band-gap energy of the second well layer is greater than that of the third well layer, and band-gap energy of the second protrusion part is greater than that of the third well layer.

8. The light emitting diode of claim 5, wherein an indium composition ratio of the first protrusion part is lower than that of the second protrusion part.

9. The light emitting diode of claim 2, wherein the first well layer is In_xGa_1-xN, and the indium composition ratio X at the center of the first well layer is 0.06 or more and 0.065 or less.

10. The light emitting diode of claim 2, wherein the second well layer is In_yGa_1-yN, and the indium composition ratio Y at the center of the second well layer is 0.12 or more and 0.13 or less.

11. The light emitting diode of claim 5, wherein the third well layer is In_zGa_1-zN, and the indium composition ratio Z at the center of the third well layer is 0.17 or more and 0.19 or less.

12. The light emitting diode of claim 2, wherein the first protrusion part is In_qGa_1-qN, and the indium composition ratio Q of the first protrusion part is 0.03 or more and 0.05 or less.

13. The light emitting diode of claim 5, wherein the second protrusion part is In_wGa_1-wN, and the indium composition ratio W of the second protrusion part is 0.09 or more and 0.11 or less.

14. A lighting system comprising the light emitting diode of claim 1.

15. A light emitting diode comprising:

a substrate;

a first conductive semiconductor layer on the substrate;

an active layer on the first conductive semiconductor layer; and

a light emitting structure, including a second conductive semiconductor layer on the active layer, wherein the active layer comprises at least one quantum well layer and at least one quantum barrier layer, wherein the at least one quantum well layer comprises a first well layer adjacent to the quantum barrier layer, a second well layer, and a third well layer having different indium composition ratios, the second well layer is disposed between the first well layer and the third well layer, wherein the at least one quantum well layer comprises a first protrusion part between the first well layer and the second well layer, and a second protrusion part between the second well layer and the third well layer, wherein an indium composition ratio of the second protrusion part is greater than that of the first protrusion part, wherein a width of the at least one quantum well layer is 3.0 nm or more and 3.5 nm or less, a width of the at least one quantum barrier layer is 4.5 nm or more and 5.5 nm or less, and a width of the first well layer is 0.6 nm or more and 0.7 nm or less, wherein the first and second protrusion parts are a region of a band-gap energy of the at least one quantum well layer.

16. The light emitting diode of claim 15, wherein a indium composition ratio of the first well layer is lower than that of the second well layer, the indium composition ratio of the second well layer is lower than that of the third well layer, and an indium composition ratio of the first protrusion part is lower than that of the second protrusion part.

17. A light emitting diode comprising:

a first conductive semiconductor layer;

a second conductive semiconductor layer on the first conductive semiconductor layer;

an active layer between the first conductive semiconductor layer and the second conductive semiconductor layer, wherein the active layer comprises a first quantum barrier layer, a second quantum barrier layer on the first quantum barrier layer, and a quantum well layer between the first quantum barrier layer and the second quantum barrier layer, wherein the quantum well layer includes a plurality of well layers and a plurality of protrusion parts, wherein the plurality of well layers and the plurality of protrusion parts include an InGaN semiconductor and have a smaller band-gap energy than a band-gap energy of the first and second quantum barrier layers, wherein each of the plurality of protrusion parts is disposed between the plurality of well layers, wherein one of plurality of well layers is disposed at a center portion of the quantum well layer, wherein each of the plurality of protrusion parts has a lower indium composition ratio than that of the plurality of well layers, wherein a band-gap energy of each of the plurality of protrusion parts is smaller than that of the quantum barrier layer, wherein the plurality of protrusion parts are a region of a band-gap energy of the quantum well layer.

18. The light emitting diode of claim 17, wherein the plurality of protrusion parts includes a first protrusion part between the first barrier layer and the center portion of the quantum well layer, a second protrusion part between the second barrier layer and the center portion of the quantum well layer, and

wherein the first protrusion part has the same indium composition ratio as the second protrusion part.

19. The light emitting diode of claim 18, wherein the plurality of well layers comprises a first well layer between the first protrusion part and the first quantum barrier layer, a second well layer between the second protrusion part and the second quantum barrier layer, and a third well layer between the first well layer and the second well layer,

wherein an indium composition ratio of a center portion of the second well layer is smaller than an indium composition ration of a center potion of the first well layer,

wherein an indium composition ratio of a center portion of the third well layer is smaller than the indium composition ration of the center potion of the second well layer,

wherein an indium composition ratio of the first protrusion part is smaller than the indium composition ration of the center potion of the first well layer, and

wherein an indium composition ratio of the second protrusion part is smaller than the indium composition ration of the center potion of the second well layer.

20. The light emitting diode of claim 17, wherein the protrusion parts include an upper protrusion parts which has a first indium composition ratio, and a lower protrusion parts which has a second indium composition ratio, and

wherein the second indium composition ration is smaller than the first indium composition ratio.