Light emitting device, light emitting device package, and illumination system
Disclosed are a light emitting device, a light emitting device package, and an illumination system. The light emitting device includes a substrate; a light emitting structure layer including a first conductive type semiconductor layer formed on the substrate and having first and second upper surfaces, in which the second upper surface is closer to the substrate than the first upper surface, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer; a second electrode on the second conductive type semiconductor layer; and at least one first electrode extending at least from the second upper surface of the first conductive type semiconductor layer to a lower surface of the substrate by passing through the substrate.
1. A light emitting device comprising:
a substrate;
a light emitting structure layer including a first conductive type semiconductor layer formed on the substrate and having first and second upper surfaces, in which the second upper surface is closer to the substrate than the first upper surface, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer;
a second electrode on the second conductive type semiconductor layer;
a plurality of first electrodes extending at least from the second upper surface of the first conductive type semiconductor layer to a lower surface of the substrate by passing through the substrate;
an inclined side surface between the first and the second upper surfaces of the first conductive type semiconductor layer; and
a first conductive layer disposed on the second upper surface of the first conductive type semiconductor layer and the inclined side surface and connected to the plurality of first electrodes,
wherein the upper portions of the plurality of first electrodes are spaced apart from each other.
2. The light emitting device of claim 1 , further comprising at least one first semiconductor layer between the first conductive type semiconductor layer and the substrate, wherein the second upper surface of the first conductive type semiconductor layer is formed of a stepped surface from at least one side surface of the active layer.
3. The light emitting device of claim 2 , wherein a portion of the first semiconductor layer is extended outward from a side surface of the first conductive type semiconductor layer, and a third conductive layer is connected to a portion of the first electrode by passing through the first semiconductor layer.
4. The light emitting device of claim 1 , wherein a lower width of the first electrode is equal to or wider than an upper width of the first electrode.
5. The light emitting device of claim 1 ,
wherein the first conductive layer connects upper portions of the plurality of first electrodes to each other,
wherein the first conductive layer is contacted with the second upper surface of the first conductive type semiconductor layer.
6. The light emitting device of claim 1 , wherein the first electrode includes a structure perpendicular or inclined with respect to a lower surface of the first conductive type semiconductor layer.
7. The light emitting device of claim 1 , wherein the second electrode is closer to an edge region of an upper surface of the second conductive type semiconductor layer than to a center region of the upper surface of the second conductive type semiconductor layer.
8. The light emitting device of claim 1 , further comprising a second conductive layer for connecting lower portions of at least two first electrodes to each other.
9. The light emitting device of claim 1 , wherein an at least one of upper and lower surface of the substrate includes a concavo-convex structure.
10. The light emitting device of claim 1 , further comprising a current spreading layer between at least a part of the second electrode and the second conductive type semiconductor layer.
11. A light emitting device comprising:
a substrate including a transmittive material;
a light emitting structure layer including a first conductive type semiconductor layer disposed on the substrate and having an outer portion stepped from at least one side of the substrate, an active layer on an inner portion of the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer;
a second electrode on the second conductive type semiconductor layer; and
a plurality of first electrodes extending from a lower surface of the substrate to a side surface of the outer portion of the first conductive type semiconductor layer by passing through the substrate.
12. The light emitting device of claim 11 , wherein the first electrodes extend to an upper surface of the outer portion of the first conductive type semiconductor layer while being spaced apart from each other, and the upper surface of the outer portion of the first conductive type semiconductor layer includes a Ga-face.
13. The light emitting device of claim 11 , wherein a width of the active layer and an upper surface of the first conductive type semiconductor layer is narrower than a width of an upper surface of the substrate.
14. The light emitting device of claim 11 , wherein the first electrodes include an electrode extending from the lower surface of the substrate to an upper surface of the substrate and a conductive layer extending to an upper surface of the electrode and the side surface of the outer portion of the first conductive type semiconductor layer.
15. The light emitting device of claim 11 , wherein an at least one of upper and lower surfaces of the substrate includes a concavo-convex structure.
16. The light emitting device of claim 15 , further comprising a reflective layer connecting the first electrodes to the lower surface of the substrate.
17. The light emitting device of claim 11 , wherein the first conductive type semiconductor layer includes an N type semiconductor layer and the second conductive type semiconductor layer includes a P type semiconductor layer.
18. The light emitting device of claim 11 , wherein the second electrode includes at least one pad and has a continuous or discontinuous loop shape branching from the pad.
19. A light emitting device comprising:
a substrate;
a light emitting structure layer including a first conductive type semiconductor layer formed on the substrate and having first and second upper surfaces, in which the second upper surface is closer to the substrate than the first upper surface, an active layer on the first conductive type semiconductor layer, and a second conductive type semiconductor layer on the active layer;
a second electrode on the second conductive type semiconductor layer;
a plurality of first electrodes extending at least from the second upper surface of the first conductive type semiconductor layer to a lower surface of the substrate by passing through the substrate; and
a first conductive layer connecting upper portions of the plurality of first electrodes to each other,
wherein the first conductive layer is contacted with the second upper surface of the first conductive type semiconductor layer,
wherein the upper portions of the plurality of first electrodes are spaced apart from each other, and
wherein the second upper surface of the first conductive type semiconductor layer is formed of a stepped surface from at least one side surface of the active layer.
20. The light emitting device of claim 19 , further comprising a second conductive layer for connecting lower portions of the plurality of first electrodes to each other,
wherein the second conductive layer is contacted with the lower surface of the substrate.