Semiconductor light-emitting device
A semiconductor light-emitting device including an N-type semiconductor layer, a plurality of P-type semiconductor layers, a light-emitting layer, and a contact layer is provided. The light-emitting layer is disposed between the N-type semiconductor layer and the whole of the P-type semiconductor layers. The P-type semiconductor layers are disposed between the contact layer and the light-emitting layer. All the P-type semiconductor layers between the light-emitting layer and the contact layer include aluminum.
1. A semiconductor light-emitting device, comprising:
an N-type semiconductor layer;
a plurality of P-type semiconductor layers;
a light-emitting layer, disposed between the N-type semiconductor layer and the whole of the P-type semiconductor layers; and
an indium gallium nitride (InGaN) contact layer, wherein the P-type semiconductor layers are disposed between the InGaN contact layer and the light-emitting layer,
wherein all the P-type semiconductor layers between the light-emitting layer and the InGaN contact layer comprise aluminum, and the P-type semiconductor layers further comprise:
a first P-type super lattice layer; and
a P-type indium aluminum gallium nitride (InAlGaN) layer, disposed between the light-emitting layer and the first P-type super lattice layer, wherein the first P-type super lattice layer is disposed between the P-type InAlGaN layer and the InGaN contact layer,
wherein the first P-type super lattice layer comprises a plurality of first P-type aluminum gallium nitride (AlGaN) layers and a plurality of second P-type AlGaN layers which are alternately stacked, and concentration of a P-type dopant in each of the first P-type AlGaN layers is different from concentration of a P-type dopant in each of the second P-type AlGaN layers,
wherein the concentration of the P-type dopant in each of the first P-type AlGaN layers falls within a range from 10 19 atoms/cm 3 to 10 20 atoms/cm 3 and a mole ratio of aluminum therein falls within a range of 10˜15%, and the concentration of the P-type dopant in each of the second P-type AlGaN layers falls within a range from 5×10 18 atoms/cm 3 to 5×10 19 atoms/cm 3 and a mole ratio of aluminum therein falls within a range of 1˜5%,
wherein the P-type semiconductor layers further comprise a second P-type super lattice layer disposed between the first P-type super lattice layer and the InGaN contact layer, and concentration of aluminum in the second P-type super lattice layer is lower than concentration of aluminum in the first P-type super lattice layer,
wherein the second P-type super lattice layer comprises a plurality of third P-type AlGaN layers and a plurality of fourth P-type AlGaN layers which are alternately stacked, and concentration of a P-type dopant in each of the third P-type AlGaN layers is different from concentration of a P-type dopant in each of the fourth P-type AlGaN layers,
wherein the concentration of the P-type dopant in each of the third P-type AlGaN layers falls within a range from 10 19 atoms/cm 3 to 5×10 19 atoms/cm 3 and a mole ratio of aluminum therein falls within a range of 3˜8%, and the concentration of the P-type dopant in each of the fourth P-type AlGaN layers falls within a range from 5×10 18 atoms/cm 3 to 10 19 atoms/cm 3 and a mole ratio of aluminum therein falls within a range of 1˜3%, and
wherein a doping concentration in the contact layer is greater than a doping concentration in each of the plurality of p-type semiconductors layers.
2. The semiconductor light-emitting device according to claim 1 , wherein the P-type dopant of the P-type semiconductor layers is a group IIA element dopant.
3. The semiconductor light-emitting device according to claim 2 , wherein the group IIA element dopant is a magnesium (Mg) dopant.
4. The semiconductor light-emitting device according to claim 1 , wherein the InGaN contact layer is an ohmic contact layer.
5. The semiconductor light-emitting device according to claim 1 , further comprising:
a first electrode, electrically connected to the N-type semiconductor layer; and
a second electrode, disposed on the InGaN contact layer.
6. The semiconductor light-emitting device according to claim 1 , wherein light emitted from the light-emitting layer comprises blue light, ultraviolet (UV) light or a combination thereof.