Method of fabricating AC light emitting device having photonic crystal structure
View Patent ↗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.
1. A method of fabricating an AC light emitting device, comprising:
forming an initial first semiconductor layer of a first conductivity type, an initial second semiconductor layer of a second conductivity type that is opposite to the first conductivity type, and an initial active layer that is disposed between the initial first semiconductor layer and the initial second semiconductor layer, on a substrate;
patterning the initial second semiconductor layer, the initial active layer, and the initial first semiconductor layer, to form a plurality of light emitting cells, each including first semiconductor layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed directly on the active layer;
patterning the second semiconductor layers, to form a photonic crystal structure in the second semiconductor layers; and
forming metallic wirings electrically connecting the light emitting cells with one another,
wherein the photonic crystal structure is formed in only the second semiconductor layers.
2. The method as claimed in claim 1 , wherein the photonic crystal structure is formed by etching the second semiconductor layers.
3. The method as claimed in claim 2 , further comprising forming transparent electrodes on the second semiconductor layers.
4. The method as claimed in claim 3 , further comprising:
forming first electrode pads on exposed regions of the first semiconductor layers; and
forming second electrode pads on the transparent electrodes,
wherein the metallic wirings connect the first and second electrode pads of adjacent ones of the light emitting cells.
5. The method as claimed in claim 1 , wherein the patterning of the second semiconductor layers comprises forming holes or rods in the second semiconductor layers.
6. A method of fabricating an AC light emitting device, comprising:
forming an initial first semiconductor layer of a first conductivity type, an initial second semiconductor layer of a second conductivity type that is opposite to the first conductivity type, and an initial active layer disposed between the initial first semiconductor layer and the initial second semiconductor layer, on a substrate;
patterning the initial second semiconductor layer, to form a photonic crystal structure in the initial second semiconductor layer;
patterning the initial second semiconductor layer, the initial active layer, and the initial first semiconductor layer, to form a plurality of light emitting cells, each including a first semiconductor layer, an active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed directly on the active layer; and
forming metallic wirings electrically connecting the light emitting cells with one another,
wherein the photonic crystal structure is formed in only the second semiconductor layers.
7. The method as claimed in claim 6 , further comprising forming transparent electrodes on the second semiconductor layers.
8. The method as claimed in claim 7 , further comprising further comprising:
forming first electrode pads on exposed regions of the first semiconductor layers; and
forming second electrode pads on the transparent electrodes,
wherein the metallic wirings connect the first and second electrode pads of adjacent ones of the light emitting cells.