Light-emitting device having a patterned surface
View Patent ↗The disclosure provides a light-emitting device. The light-emitting device comprises: a substrate having a first patterned unit; and a light-emitting stack on the substrate and having an active layer with a first surface; wherein the first patterned unit, protruding in a direction from the substrate to the light-emitting stack, has side surfaces abutting with each other and substantially non-parallel to the first surface in cross-sectional view, and has a non-polygon shape in top view.
1. A light-emitting device comprising:
a substrate having a top surface and a first patterned unit bulged on the top surface; and
a light-emitting stack formed on the substrate and having an active layer with a first surface substantially parallel to the top surface;
wherein a base of the first patterned unit has a non-polygon shape in a top view, and in a cross-sectional view the first patterned unit has a vertex, a first inclined line segment, and a second inclined line segment, and the first inclined line segment and the second inclined line segment connect at the vertex.
2. The light-emitting device according to claim 1 , wherein the non-polygon shape is a first circular shape.
3. A light-emitting device comprising:
a substrate having a top surface and a first patterned unit bulged on the top surface; and
a light-emitting stack formed on the substrate and having an active layer with a first surface substantially parallel to the top surface,
wherein the first patterned unit has a non-polygon in a top view, and a first inclined line and a second inclined line directly connected to the top surface to form a vertex in a cross-sectional view, and
wherein the first patterned unit is substantially formed in a V-shape in the cross-sectional view.
4. The light-emitting device according to claim 2 , further comprising a second patterned unit, wherein a base of the second patterned unit has a second circular shape in the top view.
5. The light-emitting device according to claim 4 , wherein the second circular shape has an area different from that of the first circular shape.
6. The light-emitting device according to claim 1 , wherein the first patterned unit is between the substrate and the light-emitting stack.
7. The light-emitting device according to claim 6 , further comprising an undoped semiconductor layer formed on the substrate and enclosing the first patterned unit.
8. The light-emitting device according to claim 1 , wherein the first patterned unit has a width and a depth smaller than the width.
9. The light-emitting device according to claim 1 , wherein the substrate comprises GaP, sapphire, GaN, or AlN.
10. The light-emitting device according to claim 1 , wherein the first inclined line segment and second inclined line segment are substantially straight lines.
11. The light-emitting device according to claim 1 , wherein the substrate comprises a non-patterned area parallel to the first surface and not greater than 10% of a total area of the substrate.
12. The light-emitting device according to claim 1 , further comprising a neighboring material with a refraction index different from that of the substrate.
13. The light-emitting device according to claim 4 , wherein the first patterned unit is adjacent to the second patterned unit.
14. A light-emitting device comprising:
a substrate having a top surface and a plurality of first patterned units bulged on the top surface; and
a light-emitting stack formed on the substrate and having an active layer with a first surface substantially parallel to the top surface,
wherein each of the plurality of first patterned units has a non-polygon shape in a top view, and a first inclined line and a second inclined line directly connected to the top surface to form a vertex in a cross-sectional view, and
wherein each of the plurality of first patterned units is substantially formed in a V-shape in the cross-sectional view.
15. The light-emitting device according to claim 14 , wherein one of the plurality of first patterned units is adjacent to another one of the plurality of first patterned units.
16. The light-emitting device according to claim 14 , further comprising a plurality of second patterned unit, wherein the plurality of first patterned units and the plurality of second patterned unit are arranged in a row.