Semiconductor light emitting device
View Patent ↗According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting part. The n-type semiconductor layer includes a nitride semiconductor. The p-type semiconductor layer includes a nitride semiconductor. The light emitting part is provided between the n-type and the p-type semiconductor layers and includes an n-side barrier layer and a first light emitting layer. The first light emitting layer includes a first barrier layer, a first well layer, and a first AlGaN layer. The first barrier layer is provided between the n-side barrier layer and the p-type semiconductor layer. The first well layer contacts the n-side barrier layer between the n-side and the first barrier layer. The first AlGaN layer is provided between the first well layer and the first barrier layer. A peak wavelength λp of light emitted from the light emitting part is longer than 515 nanometers.
1. A semiconductor light emitting device, comprising:
an n-type semiconductor layer including a nitride semiconductor;
a p-type semiconductor layer including a nitride semiconductor; and
a light emitting part provided between the n-type semiconductor layer and the p-type semiconductor layer and including an n-side barrier layer and a first light emitting layer,
the first light emitting layer including:
a first barrier layer provided between the n-side barrier layer and the p-type semiconductor layer;
a first well layer contacting the n-side barrier layer between the n-side barrier layer and the first barrier layer; and
a first AlGaN layer provided between the first well layer and the first barrier layer, the first AlGaN layer having a layered-form and including Al z1 Ga 1−z1 N (0.25<z1≦1),
a peak wavelength λp of light emitted from the light emitting part being longer than 515 nanometers.
2. The device according to claim 1 , wherein a thickness of the first AlGaN layer has an RMS value of 0.5 nanometers or less.
3. The device according to claim 1 , wherein a major surface of the n-type semiconductor layer is a c-face.
4. The device according to claim 1 , wherein the first light emitting layer further includes a first cap layer contacting the first AlGaN layer and the first barrier layer and including a nitride semiconductor.
5. The device according to claim 1 , wherein in the first AlGaN layer, an area of recessed regions or regions having through holes formed occupies less than 10% of a layer surface of the first AlGaN layer.
6. The device according to claim 1 , wherein
the first barrier layer includes In x1 Ga 1−x1 N(0≦x1<1), and
the n-side barrier layer includes In x2 Ga 1−x2 N(0≦x2<1).
7. The device according to claim 1 , wherein the light emitting part further includes a second light emitting layer,
the second light emitting layer including:
a second barrier layer provided between the first barrier layer and the p-type semiconductor layer;
a second well layer contacting the first barrier layer between the first barrier layer and the second barrier layer; and
a second AlGaN layer provided between the second well layer and the second barrier layer, the second AlGaN layer having a layered-form and including Al z2 Ga 1−z2 N (0.25<z2≦1).
8. The device according to claim 1 , wherein a thickness of the first well layer is 1.0 nanometer or more and 5.0 nanometers or less.
9. The device according to claim 1 , wherein a thickness of the first barrier layer is 3 nanometers or more and 50 nanometers or less.
10. The device according to claim 1 , wherein a thickness of the n-side barrier layer is 3 nanometers or more and 20 nanometers or less.
11. A semiconductor light emitting device, comprising:
an n-type semiconductor layer including a nitride semiconductor;
a p-type semiconductor layer including a nitride semiconductor; and
a light emitting part provided between the n-type semiconductor layer and the p-type semiconductor layer and including an n-side barrier layer and a first light emitting layer,
the first light emitting layer including:
a first barrier layer provided between the n-side barrier layer and the p-type semiconductor layer;
a first well layer contacting the n-side barrier layer between the n-side barrier layer and the first barrier layer; and
a first AlGaN layer provided between the first well layer and the first barrier layer, the first AlGaN layer having a layered-form and including Al z1 Ga 1−z1 N (0<z1≦1),
an Al composition ratio z1 in group III of the first AlGaN layer and a peak wavelength λp (nanometer) of light emitted from the light emitting part satisfying a condition of
1.15 z 1>0.0024 λp− 0.972>0.90 z 1.
12. The device according to claim 11 , wherein a thickness of the first AlGaN layer has an RMS value of 0.5 nanometers or less.
13. The device according to claim 11 , wherein a major surface of the n-type semiconductor layer is a c-face.
14. The device according to claim 11 , wherein the first light emitting layer further includes a first cap layer contacting the first AlGaN layer and the first barrier layer and including a nitride semiconductor.
15. The device according to claim 11 , wherein in the first AlGaN layer, an area of recessed regions or regions having through holes formed occupies less than 10% of a layer surface of the first AlGaN layer.
16. The device according to claim 11 , wherein
the first barrier layer includes In x1 Ga 1−x1 N(0≦x1<1), and
the n-side barrier layer includes In x2 Ga 1−x2 N(0≦x2<1).
17. The device according to claim 11 , wherein
the light emitting part further includes a second light emitting layer,
the second light emitting layer including:
a second barrier layer provided between the first barrier layer and the p-type semiconductor layer;
a second well layer contacting the first barrier layer between the first barrier layer and the second barrier layer; and
a second AlGaN layer provided between the second well layer and the second barrier layer, the second AlGaN layer having a layered-form and including Al z2 Ga 1−z2 N (0.25<z2≦1).
18. The device according to claim 11 , wherein a thickness of the first well layer is 1.0 nanometer or more and 5.0 nanometers or less.
19. The device according to claim 18 , wherein a thickness of the first barrier layer is 3 nanometers or more and 50 nanometers or less.
20. The device according to claim 19 , wherein a thickness of the n-side barrier layer is 3 nanometers or more and 20 nanometers or less.