Ac Light Emitting Device Having Photonic Crystal Structure and Method of Fabricating the Same

• US 20080237613A1
• Filed: 09/06/2006
• Published: 10/02/2008
• Est. Priority Date: 11/10/2005
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Lee, Jae Ho, Hwang, Eu Jin, Lee, Jun Hee, Kim, Jong Kyu, Yoon, Yeo Jin
• Granted Patent: US 8,716,727 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

Disclosed is an AC light emitting device having photonic crystal structures and a method of fabricating the same. The light emitting device includes a plurality of light emitting cells and metallic wirings electrically connecting the light emitting cells with one another. Further, each of the light emitting cells includes a first conductive type semiconductor layer, a second conductive type semiconductor layer disposed on one region of the first conductive type semiconductor layer, and an active layer interposed between the first and second conductive type semiconductor layers. In addition, a photonic crystal structure is formed in the second conductive type semiconductor layer. The photonic crystal structure prevents light emitted from the active layer from laterally propagating by means of a periodic array, such that light extraction efficiency of the light emitting device can be improved. Furthermore, the metallic wirings electrically connect a plurality of light emitting cells with one another such that an AC light emitting device can be provided.

Claims

1. An AC light emitting device, comprising:

a plurality of light emitting cells each including a first conductive type semiconductor layer, a second conductive type semiconductor layer disposed on one region of the first conductive type semiconductor layer, an active layer interposed between the first and second conductive type semiconductor layers, and a photonic crystal structure formed in the second conductive type semiconductor layer; and

metallic wirings electrically connecting the plurality of light emitting cells with one another.

2. The device as claimed in claim 1, wherein the photonic crystal structure includes a lattice of holes two dimensionally arranged.

3. The device as claimed in claim 1, wherein the photonic crystal structure includes a periodic unevenness formed in the second conductive type semiconductor layer.

4. The device as claimed in claim 1, wherein the photonic crystal structure includes a lattice of second conductive type semiconductor rods.

5. The device as claimed in claim 1, further comprising first electrode pads formed on other regions of the first conductive type semiconductor layers, transparent electrodes for covering the second conductive type semiconductor layers, and second electrode pads formed on the transparent electrodes, wherein each of the metallic wirings connects the first and second electrode pads of the adjacent light emitting cells.

6. A method of fabricating an AC light emitting device, comprising:

forming a first conductive type semiconductor layer, an active layer and a second conductive type semiconductor layer on a substrate;

patterning the second conductive type semiconductor layer, the active layer and the first conductive type semiconductor layer to form a plurality of light emitting cells each including an isolated first conductive type semiconductor layer, a second conductive type semiconductor layer disposed on one region of the isolated first conductive type semiconductor layer, an active layer interposed between the isolated first conductive type semiconductor layer and the second conductive type semiconductor layer, and a photonic crystal structure formed in the second conductive type semiconductor layer; and

forming metallic wirings electrically connecting the light emitting cells having the photonic crystal structures with one another.

7. The method as claimed in claim 6, wherein the photonic crystal structure is formed by etching the second conductive type semiconductor layer.

8. The method as claimed in claim 7, further comprising formation of transparent electrodes on the second conductive type semiconductor layers with the photonic crystal structures formed therein.

9. The method as claimed in claim 8, further comprising:

forming first electrode pads on other regions of the first conductive type semiconductor layers; and

forming second electrode pads on the transparent electrodes,

wherein the metallic wirings connect the first and second electrode pads of the adjacent light emitting cells.