Silicon based light emitting diode

• US 7,671,377 B2
• Filed: 11/14/2005
• Issued: 03/02/2010
• Est. Priority Date: 12/08/2004
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Tae-Youb, Kim, Kyung-Hyun, Sung, Gun-Yong, Park, Nae-Man
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Joy; Jeremy J
• Application Number:
  US11/720,987
• Publication Number:
  US 20090242913A1
• Time in Patent Office: 1,569 Days
• Field of Search: 257/98, 257/E51.021, 257/E33.069, 257/103, 257/618, 257/623, 257/625, 257/626, 438/72
• US Class Current: 257/98
• CPC Class Codes: H01L 33/34 containing only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/465 with a resonant cavity structure

Abstract

Provided is a highly efficient silicon-based light emitting diode (LED) including a Distributed Bragg Reflector (DBR), an n-type doping layer, and a p-type substrate structure. The silicon-based LED includes: a substrate having a p-type mesa substrate structure; an active layer that is formed on the substrate and has a first surface and a second surface opposite the first surface; a first reflective layer facing the first surface of the active layer; a second reflective layer that is located on either side of the p-type substrate structure and faces the second surface of the active layer; an n-type doping layer sandwiched between the active layer and the first reflective layer; a first electrode electrically connected to the n-type doping layer; and a second electrode electrically connected to the p-type substrate structure.

Claims

1. A silicon-based light emitting diode (LED), comprising:

a substrate having a p-type mesa substrate structure;

an active layer that is formed on the substrate and has a first surface and a second surface opposite the first surface;

a first reflective layer facing the first surface of the active layer;

a second reflective layer that is located on either side of the p-type mesa substrate structure and faces the second surface of the active layer;

an n-type doping layer sandwiched between the active layer and the first reflective layer;

a first electrode electrically connected to the n-type doping layer; and

a second electrode electrically connected to the p-type mesa substrate structure.

2. The LED of claim 1, wherein the p-type mesa substrate structure penetrates the second reflective layer and contacts the second surface of the active layer.

3. The LED of claim 2, wherein the first electrode surrounds the first reflective layer, and

wherein the p-type mesa substrate structure is located below a portion of the first reflective layer surrounded by the first electrode.

4. The LED of claim 1, wherein the first electrode is formed on the n-type doping layer and is shaped to completely surround the first reflective layer.

5. The LED of claim 4, wherein the first electrode has a top of ring shape or polygonal shape.

6. The LED of claim 4, further comprising a light-emitting region located within the portion of the first reflective layer surrounded by the first electrode.

7. The LED of claim 1, wherein the p-type mesa substrate structure has a width of 0.01 to 10 mm.

8. The LED of claim 1, wherein the first and second reflective layers each include a Distributed Bragg Reflector (DBR) consisting of a stack of alternating layers of silicon-containing insulating materials having different compositions.

9. The LED of claim 8, wherein the first and second reflective layers are respectively composed of first and second insulating layers having different compositions, and the refractive index difference between the first and second insulating layers is 0.1 to 1.5.

10. The LED of claim 9, wherein the first and second reflective layers each include 2 to 20 pairs of first and second insulating layers.

11. The LED of claim 8, wherein the first and second reflective layers are each composed of a repeated stack of alternating layers of silicon oxide and silicon nitride.

12. The LED of claim 1, wherein the n-type doping layer is formed of an n-type compound semiconductor.

13. The LED of claim 12, wherein the n-type doping layer is made of a compound selected from the group consisting of ZnO, InSnO, NiO, SiC, and SnO₂.

14. The LED of claim 1, wherein the active layer is formed of crystalline or amorphous silicon nano-size dots.

15. The LED of claim 1, wherein the active layer has a thickness of 10 nm to 100 μ

m.

16. The LED of claim 1, wherein the first and second electrodes are each made of a metal layer having a thickness of 100 μ

m to 5 mm.