Light-emitting element having a reflective structure with high efficiency
View Patent ↗An optoelectronic element comprises a semiconductor stack comprising an active layer, wherein the semiconductor stack has a first surface and a second surface opposite to the first surface; a first transparent layer on the second surface; a plurality of cavities in the first transparent layer; and a layer on the first transparent layer, wherein the first transparent layer comprises oxide or diamond-like carbon.
1. An optoelectronic element, comprising:
a semiconductor stack comprising an active layer, wherein the semiconductor stack has a first surface and a second surface opposite to the first surface;
a first transparent layer on the second surface;
a plurality of cavities in the first transparent layer; and
a layer on the first transparent layer;
wherein the first transparent layer comprises oxide or diamond-like carbon,
wherein the second surface comprises a second rough portion and a second flat portion, and one of the cavities is on the second rough portion, and
wherein the first surface comprises a first flat portion and a first rough portion, and the electrode is on the first flat portion.
2. The optoelectronic element according to claim 1 , wherein the second flat portion and the first transparent layer form an ohmic contact.
3. The optoelectronic element according to claim 1 , wherein a refractive index of the cavity is smaller than that of the first transparent layer and the semiconductor stack.
4. The optoelectronic element according to claim 1 , wherein the layer comprises a surface facing the semiconductor stack, and the surface has an average roughness of the center line between 1 nm and 40 nm.
5. The optoelectronic element according to claim 1 , further comprising a second transparent layer between the first transparent layer and the layer.
6. The optoelectronic element according to claim 5 , wherein the second transparent layer has a thickness larger than that of the first transparent layer.
7. The optoelectronic element according to claim 1 , wherein the layer comprises a material selected from Copper (Cu), Aluminum (Al), Gold (Au), Silver (Ag) or the alloy thereof.
8. The optoelectronic element according to claim 1 , wherein the semiconductor stack comprises a window layer.
9. The optoelectronic element according to claim 8 , wherein the window layer comprises GaP.
10. The optoelectronic element according to claim 1 , further comprising a substrate on the layer, and an adhesive layer between the substrate and the layer for connecting thereof.
11. The optoelectronic element according to claim 1 , wherein the first transparent layer comprises a plurality of channels.
12. An optoelectronic element, comprising:
a semiconductor stack comprising an active layer, wherein the semiconductor stack has a first surface and a second surface opposite to the first surface;
a first transparent layer on the second surface;
a plurality of cavities in the first transparent layer;
a layer on the first transparent layer;
a first conductive layer on the layer; and
a second conductive layer on the layer;
wherein the first transparent layer comprises oxide or diamond-like carbon,
wherein the first transparent layer comprises a plurality of channels, and
wherein the first conductive layer and the second conductive layer are separated.
13. The optoelectronic element according to claim 12 , wherein the first conductive layer electrically contacting with the semiconductor stack through the plurality of channels.
14. The optoelectronic element according to claim 12 , wherein the layer comprises a reflective layer.
15. The optoelectronic element according to claim 14 , further comprising a second transparent layer between the layer and the first conductive layer.
16. The optoelectronic element according to claim 1 , wherein one of the cavities has an opening facing the second surface.
17. The optoelectronic element according to claim 1 , wherein the layer covers one of the cavities.
18. An optoelectronic element, comprising:
a semiconductor stack comprising an active layer, wherein the semiconductor stack has a first surface and a second surface opposite to the first surface;
a first transparent layer on the second surface;
a plurality of cavities in the first transparent layer;
a layer on the first transparent layer; and
an electrode on the first surface,
wherein the first transparent layer comprises oxide or diamond-like carbon,
wherein the second surface comprises a second rough portion and a second flat portion, and one of the cavities is on the second rough portion,
wherein the second flat portion is right under the electrode.