Semiconductor light emitting device
A semiconductor light emitting device is provided. The semiconductor light emitting device includes a first conductive semiconductor layer; an active layer on the first conductive semiconductor layer; a first quantum dot layer on the active layer; and a second conductive semiconductor layer on the first quantum dot layer.
1. A semiconductor light emitting device comprising:
a substrate;
a first conductive type semiconductor layer on the substrate;
an active layer on the first conductive type semiconductor layer;
a first cladding layer on the active layer;
a nitride-based semiconductor layer on the first cladding layer; and
a second conductive type semiconductor layer on the nitride-based semiconductor layer,
wherein the first cladding layer and the nitride-based semiconductor layer comprise different semiconductor materials such that the nitride-based semiconductor layer has a lattice mismatch with respect to the first cladding layer, and
wherein the nitride-based semiconductor layer comprises an In-rich nitride-based semiconductor layer.
2. The semiconductor light emitting device according to claim 1 , wherein the first cladding layer comprises an AlGaN layer or an AlInGaN layer.
3. The semiconductor light emitting device according to claim 1 , wherein the nitride-based semiconductor layer is doped with an amount of In that is 10 to 500 times an amount of Ga.
4. The semiconductor light emitting device according to claim 1 , wherein the first cladding layer includes a p-AlGaN layer and the nitride-based semiconductor layer includes an InGaN layer.
5. A semiconductor light emitting device comprising:
a substrate;
a first conductive type semiconductor layer on the substrate;
an active layer on the first conductive type semiconductor layer;
a first cladding layer on the active layer;
a nitride-based semiconductor layer on the first cladding layer;
a first capping layer on the nitride-based semiconductor layer, wherein the first capping layer comprises an N-rich GaN layer or a Ga-rich GaN layer; and
a second conductive type semiconductor layer on the first capping layer,
wherein the first cladding layer and the nitride-based semiconductor layer comprise different semiconductor material such that the nitride-based semiconductor layer has a lattice mismatch with respect to the first cladding layer.
6. The semiconductor light emitting device according to claim 5 , wherein a pair of the nitride-based semiconductor layer and the first capping layer is from one to ten pairs.
7. The semiconductor light emitting device according to claim 5 , wherein at least one of the nitride-based semiconductor layer, the first cladding layer and the first capping layer comprises a second conductive type dopant.
8. A semiconductor light emitting device comprising:
a substrate;
a first conductive type semiconductor layer on the substrate;
an active layer on the first conductive type semiconductor layer;
a first cladding layer on the active layer;
a nitride-based semiconductor layer on the first cladding layer; and
a second conductive type semiconductor layer on the nitride-based semiconductor layer,
wherein the first cladding layer and the nitride-based semiconductor layer comprise different semiconductor materials such that the nitride-based semiconductor layer has a lattice mismatch with respect to the first cladding layer, and
wherein the nitride-based semiconductor layer comprises a roughness shape on a top surface thereof.
9. The semiconductor light emitting device according to claim 8 , wherein the roughness shape comprises a three-dimensional structure including a plurality of quantum dots, a diameter of the quantum dots is 50 nm to 200 nm, and a height of the quantum dots is 1 nm to 20 nm.
10. The semiconductor light emitting device according to claim 8 , wherein the concentration of the roughness is between 1×10 8 /cm 2 ˜5×10 10 /cm 2 .
11. The semiconductor light emitting device according to claim 8 , wherein the nitride-based semiconductor layer and/or the first capping layer is doped with a first conductive dopant or a second conductive dopant.
12. The semiconductor light emitting device according to claim 8 , wherein the first conductive type semiconductor layer is an n-type semiconductor layer and the second conductive type semiconductor layer is a p-type semiconductor layer and the p-type semiconductor layer is formed of at least one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN layers.
13. The semiconductor light emitting device according to claim 8 , wherein the first conductive type semiconductor layer is a p-type semiconductor layer and the second conductive type semiconductor layer is an n-type semiconductor layer.
14. The semiconductor light emitting device according to claim 8 , wherein the active layer has a single quantum well or multi quantum well (MQW) structure and is formed of Al X Ga Y In 1-X-Y N/Al X Ga Y In 1-X-Y N (0≦X, 0≦Y, X+Y≦1).
15. The semiconductor light emitting device according to claim 8 , further comprising a buffer layer between the substrate and the first conductive type semiconductor layer.
16. The semiconductor light emitting device according to claim 8 , further comprising an undoped semiconductor layer between the substrate and the first conductive type semiconductor layer.
17. The semiconductor light emitting device according to claim 8 , wherein the nitride-based semiconductor layer comprise In-rich nitride-based semiconductor layer.
18. The semiconductor light emitting device according to claim 8 , wherein the first cladding layer comprises an AlGaN layer or an AlInGaN layer.
19. The semiconductor light emitting device according to claim 8 , further comprising a first capping layer between the nitride-based semiconductor layer and the second conductive type semiconductor layer, wherein the first capping layer comprises an N-rich GaN layer or a Ga-rich GaN layer.
20. The semiconductor light emitting device according to claim 19 , wherein a pair of the nitride-based semiconductor layer and the first capping layer is from one to ten pairs.