Light emitting device
A light emitting diode of one embodiment includes a light emitting device having a plurality of N-type semiconductor layers including a first N-type semiconductor layer and a second N-type semiconductor layer on the first N-type semiconductor layer, an active layer on an upper layer of the plurality of N-type semiconductor layers, and a P-type semiconductor layer on the active layer. The first N-type semiconductor layer includes a first Si doped Nitride layer and the second N-type semiconductor layer includes a second Si doped Nitride layer. The first and second N-type semiconductor layers have a Si impurity concentration different from each other.
1. A light emitting device, comprising:
a plurality of N-type semiconductor layers including a first N-type semiconductor layer and a second N-type semiconductor layer on the first N-type semiconductor layer;
an active layer on an upper layer of the plurality of N-type semiconductor layers; and
a P-type semiconductor layer on the active layer,
wherein the first N-type semiconductor layer comprises a first Si doped Nitride layer and the second N-type semiconductor layer comprises a second Si doped Nitride layer, and
wherein the first and second N-type semiconductor layers have a Si impurity concentration different from each other.
2. The light emitting device according to claim 1 , wherein the second N-type semiconductor layer has a Si impurity concentration lower than a Si impurity concentration of the first N-type semiconductor layer.
3. The light emitting device according to claim 1 , wherein at least one of the first and second N-type semiconductor layers comprises an N-type GaN layer.
4. The light emitting device according to claim 1 , further comprising:
an undoped GaN layer on the second N-type semiconductor layer.
5. The light emitting device according to claim 1 , further comprising:
an undoped GaN layer between the second N-type semiconductor layer and the active layer.
6. The light emitting device according to claim 1 , wherein the first and second N-type semiconductor layers comprise an N-type GaN layer.
7. The light emitting device according to claim 1 , wherein the second N-type semiconductor layer has a dislocation density lower than a dislocation density of the first N-type semiconductor layer.
8. The light emitting device according to claim 1 , further comprising:
a first electrode on a first portion of the upper layer of the plurality of N-type semiconductor layer; and
a second electrode on the P-type semiconductor layer.
9. The light emitting device according to claim 8 , further comprising:
an ohmic electrode layer between the second electrode layer and the P-type semiconductor layer.
10. A light emitting device, comprising:
a plurality of N-type semiconductor layers including a first N-type semiconductor layer and a second N-type semiconductor layer on the first N-type semiconductor layer;
an active layer on a first portion of an upper layer of the plurality of N-type semiconductor layers;
a P-type semiconductor layer on the active layer,
a first electrode on a second portion of the upper layer of the plurality of N-type semiconductor layers; and
a second electrode on the P-type semiconductor layer,
wherein the first N-type semiconductor layer comprises a first Si doped Nitride layer and the second N-type semiconductor layer comprises a second Si doped Nitride layer, and
wherein the first and second N-type semiconductor layers have a Si impurity concentration different from each other.
11. The light emitting device according to claim 10 , wherein the second N-type semiconductor layer has a Si impurity concentration lower than a Si impurity concentration of the first N-type semiconductor layer.
12. The light emitting device according to claim 10 , wherein at least one of the first and second N-type semiconductor layers comprises an N-type GaN layer.
13. The light emitting device according to claim 10 , further comprising:
an undoped GaN layer on the second N-type semiconductor layer.
14. The light emitting device according to claim 10 , further comprising:
an undoped GaN layer between the second N-type semiconductor layer and the active layer.
15. The light emitting device according to claim 10 , wherein the first and second N-type semiconductor layers comprise an N-type GaN layer.
16. The light emitting device according to claim 10 , wherein the second N-type semiconductor layer has a dislocation density lower than a dislocation density of the first N-type semiconductor layer.
17. The light emitting device according to claim 10 , further comprising:
an ohmic electrode layer between the second electrode layer and the P-type semiconductor layer.
18. A light emitting device, comprising:
a sapphire substrate;
a first N-type semiconductor layer including a GaN layer on the sapphire substrate;
a second N-type semiconductor layer including a GaN layer on the first N-type semiconductor layer;
an undoped GaN layer on the second N-type semiconductor layer;
an active layer on the undoped GaN layer; and
a P-type GaN layer on the active layer,
wherein the first and second N-type semiconductor layers have a Si impurity concentration different from each other.
19. The light emitting device according to claim 18 , wherein the second N-type semiconductor layer has a Si impurity concentration lower than a Si impurity concentration of the first N-type semiconductor layer.
20. The light emitting device according to claim 18 , further comprising:
a first electrode on a first portion of the second N-type semiconductor layer; and
a second electrode on the P-type GaN layer.