Semiconductor light emitting device
View Patent ↗A semiconductor light emitting device may include an n-type contact layer on a substrate. An active layer may be on the n-type contact layer and/or include two or more quantum well layers and two or more barrier layers. A p-type contact layer may be on the active layer. Energy band gaps of the quantum well layers may be larger as the quantum well layers are closer to the n-type contact layer from the p-type contact layer, thicknesses of the quantum well layers may be smaller as the quantum well layers are closer to the n-type contact layer from the p-type contact layer, and/or energy band gaps of the barrier layers may be larger as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
1. A semiconductor light emitting device, the device comprising:
an n-type contact layer on a substrate;
an active layer on the n-type contact layer and including two or more quantum well layers and two or more barrier layers; and
a p-type contact layer on the active layer,
wherein the energy band gaps of the quantum well layers are larger as the quantum well layers are closer to the n-type contact layer from the p-type contact layer, and
if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, an atomic percentage of indium of an Nth quantum well layer is about 5-20% less than an atomic percentage of indium of an (N+1)th quantum well layer.
2. A semiconductor light emitting device, the device comprising:
an n-type contact layer on a substrate;
an active layer on the n-type contact layer and including two or more quantum well layers and two or more barrier layers; and
a p-type contact layer on the active layer,
wherein thicknesses of the quantum well layers change as the quantum well layers are closer to the n-type contact layer from the p-type contact layer, and
if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, a thickness of an Nth quantum well layer is about 5-20% less than a thickness of an (N+1)th quantum well layer.
3. A semiconductor light emitting device, the device comprising:
an n-type contact layer on a substrate;
an active layer on the n-type contact layer and including two or more quantum well layers and two or more barrier layers; and
a p-type contact layer on the active layer,
wherein energy band gaps of the barrier layers change as the barrier layers are closer to the n-type contact layer from the p-type contact layer, and
if numbers are allocated from the barrier layer closest to the n-type contact layer to the barrier layer closest to the p-type contact layer, an atomic percentage of indium of an Nth barrier layer is about 5-20% less than an atomic percentage of indium of an (N+1)th barrier layer.
4. The device of claim 1 , wherein
the quantum well layers are In x Ga 1-x N layers, and
x is a number greater than or equal to 0.05 and less than or equal to 0.5.
5. The device of claim 1 , wherein thicknesses of the quantum well layers are smaller as the quantum well layers are closer to the n-type contact layer from the p-type contact layer.
6. The device of claim 5 , wherein if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, a thickness of an Nth quantum well layer is about 5-20% less than a thickness of an (N+1)th quantum well layer.
7. The device of claim 1 , wherein energy band gaps of the barrier layers are larger as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
8. The device of claim 1 , wherein
the barrier layers are In y Ga 1-y N layers, and
y is a number greater than or equal to 0 and less than or equal to 0.1.
9. The device of claim 8 , wherein the amount of indium in the barrier layers is smaller as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
10. The device of claim 9 , wherein if numbers are allocated from the barrier layer closest to the n-type contact layer to the barrier layer closest to the p-type contact layer, an atomic percentage of indium of an Nth barrier layer is about 5-20% less than an atomic percentage of indium of an (N+1)th barrier layer.
11. The device of claim 1 , further comprising:
an electron blocking layer between the active layer and the p-type contact layer.
12. The device of claim 2 , wherein
the quantum well layers are In x Ga 1-x N layers, and
x is a number greater than or equal to 0.05 and less than or equal to 0.5.
13. The device of claim 12 , wherein an amount of indium in the quantum well layers is smaller as the quantum well layers are closer to the n-type contact layer from the p-type contact layer.
14. The device of claim 13 , wherein if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, an atomic percentage of indium of an Nth quantum well layer is about 5-20% less than an atomic percentage of indium of an (N+1)th quantum well layer.
15. The device of claim 2 , wherein energy band gaps of the barrier layers are larger as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
16. The device of claim 2 , wherein
the barrier layers are In y Ga 1-y N layers, and
y is a number greater than or equal to 0 and less than or equal to 0.1.
17. The device of claim 16 , wherein an amount of indium in the barrier layers is smaller as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
18. The semiconductor light emitting device of claim 17 , wherein if numbers are allocated from the barrier layer closest to the n-type contact layer to the barrier layer closest to the p-type contact layer, an atomic percentage of indium of an Nth barrier layer is about 5-20% less than an atomic percentage of indium of an (N+1)th barrier layer.
19. The semiconductor light emitting device of claim 2 , further comprising:
an electron blocking layer between the active layer and the p-type contact layer.
20. The device of claim 3 , wherein energy band gaps of the barrier layers are larger as the barrier layers are closer to the n-type contact layer from the p-type contact layer.
21. The device of claim 20 , wherein
the barrier layers are In y Ga 1-y N layers,
and y is greater than or equal to 0 and less than or equal to 0.1.
22. The device of claim 20 , wherein if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, a thickness of an Nth quantum well layer is about 5-20% less than a thickness of an (N+1)th quantum well layer.
23. The device of claim 20 , wherein
the quantum well layers are In x Ga 1-x N layers, and
x is a number greater than or equal to 0.05 and less than or equal to 0.5.
24. The device of claim 23 , wherein the amount of indium in the quantum well layers is smaller as the quantum well layers are closer to the n-type contact layer from the p-type contact layer.
25. The device of claim 24 , wherein if numbers are allocated from the quantum well layer closest to the n-type contact layer to the quantum well layer closest to the p-type contact layer, an atomic percentage of indium of an Nth quantum well layer is about 5-20% less than an atomic percentage of indium of an (N+1)th quantum well layer.
26. The device of claim 20 , further comprising:
an electron blocking layer between the active layer and the p-type contact layer.