Light-emitting element having a reflective structure with high efficiency
View Patent ↗A light-emitting element includes a reflective layer; a first transparent layer on the reflective layer; a light-emitting stack having an active layer on the first transparent layer; and a cavity formed in the first transparent layer.
1. A light-emitting element, comprising:
a reflective layer;
a first transparent layer located on the reflective layer;
a light-emitting stack comprising an active layer located on the first transparent layer;
a cavity formed in the first transparent layer; and
a second transparent layer located between the first transparent layer and the light-emitting stack,
wherein the cavity is formed in the first transparent layer and the second transparent layer.
2. The light-emitting element according to claim 1 , wherein the light-emitting stack comprises a rough lower surface which includes a plurality of protruding portions and concave portions, and the cavity is formed under at least one of the protruding portions.
3. The light-emitting element according to claim 1 , wherein the cavity is in a funnel shape.
4. A light-emitting element, comprising:
a reflective layer;
a first transparent layer located on the reflective layer;
a window layer comprising a rough lower surface located on the first transparent layer;
a light-emitting stack comprising an active layer located on the window layer; and
a cavity formed in the first transparent layer.
5. The light-emitting element according to claim 4 , wherein the rough lower surface includes a plurality of protruding portions and concave portions, and the cavity is formed under at least one of the protruding portions.
6. The light-emitting element according to claim 5 , wherein part of the first transparent layer is formed at the top of the protruding portion.
7. The light-emitting element according to claim 5 , wherein the height difference between the concave portions and the protruding portions is ⅓ to ⅔ the thickness of the window layer.
8. The light-emitting element according to claim 4 , further comprising a second transparent layer located between the first transparent layer and the window layer.