Light-emitting element
A light-emitting element, comprises a light-emitting stack comprising an active layer; a window layer on the light-emitting stack, wherein the window layer has a surface opposite to the light-emitting stack; and an insulative layer on the surface, wherein the surface comprises a cavity and the insulative layer substantially conformally covering the cavity, and wherein the insulative layer has a first refractive index equal to or smaller than 1.4.
1. A light-emitting element, comprising:
a light-emitting stack comprising an active layer;
a window layer on the light-emitting stack, wherein the window layer has a surface opposite to the light-emitting stack; and
an insulative layer on the surface;
wherein the surface comprises a cavity and the insulative layer substantially conformally covering the cavity;
wherein the insulative layer has a first refractive index equal to or smaller than 1.4.
2. The light-emitting element according to claim 1 , further comprising a transparent conducting structure on the insulative layer.
3. The light-emitting element according to claim 2 , further comprising a first void between the insulative layer and the transparent conducting structure.
4. The light-emitting element according to claim 3 , wherein the light-emitting stack further comprises a first semiconductor layer and a second semiconductor layer, and the active layer is between the first semiconductor layer and the second semiconductor layer.
5. The light-emitting element according to claim 4 , wherein the window layer connects the first semiconductor layer.
6. The light-emitting element according to claim 5 , wherein the cavity exposes the first semiconductor layer.
7. The light-emitting element according to claim 6 , wherein the first semiconductor layer comprises a second void connecting the cavity.
8. The light-emitting element according to claim 7 , wherein the second void overlaps the insulative layer in a stacking direction of the light-emitting stack.
9. The light-emitting element according to claim 7 , wherein the second void overlaps the first void in a stacking direction of the light-emitting stack.
10. The light-emitting element according to claim 3 , wherein the insulative layer comprises a plurality of pores and the transparent conducting structure directly contacts the window layer through the pores.
11. The light-emitting element according to claim 10 , wherein the first void is arranged between the pores.
12. The light-emitting element according to claim 4 , wherein the first semiconductor layer comprises AlInP and the window comprises GaP.
13. The light-emitting element according to claim 1 , wherein the first insulative layer comprises magnesium fluoride.
14. A light-emitting element, comprising:
a light-emitting stack comprising an active layer;
a window layer on the light-emitting stack, wherein the window layer has a surface opposite to the light-emitting stack;
an insulative layer on the surface;
a transparent conducting structure on the insulative layer; and
a first void between the transparent conducting structure and the insulative layer,
wherein the first void has a second refractive index lower than 1.2.
15. The light-emitting element according to claim 14 , wherein the insulative layer has a first refractive index equal to or smaller than 1.4.
16. The light-emitting element according to claim 14 , wherein the surface comprises a cavity.
17. The light-emitting element according to claim 16 , wherein the insulative layer substantially conformally covers the cavity.
18. The light-emitting element according to claim 16 , wherein the first void is disposed in the cavity.
19. The light-emitting element according to claim 16 , wherein the window layer comprises a second void connecting the cavity.
20. The light-emitting element according to claim 19 , wherein the second void and the first void are separated by the transparent conducting structure or the insulative layer.