Light-emitting device
This disclosure discloses a light-emitting device. The light-emitting device includes a light-emitting stack having a first-type semiconductor layer, a second-type semiconductor layer, and an active layer formed between the first-type semiconductor layer and the second-type semiconductor layer; and a reflective structure formed on the first-type semiconductor layer and having a first interface and a second interface. A critical angle at the first interface for a light emitted from the light-emitting stack is larger than that at the second interface. The reflective structure electrically connects to the first-type semiconductor layer at the first interface, and an area of the first interface is more than an area of the second interface in a top view.
1. A light-emitting device, comprising:
a substrate;
a bonding structure on the substrate and comprising a first bonding layer;
a light-emitting stack on the bonding structure and having a first-type semiconductor layer, a second-type semiconductor layer, and an active layer between the first-type semiconductor layer and the second-type semiconductor layer;
a reflective structure between the first-type semiconductor layer and the substrate and having a first interface and a second interface; and
a void embedded within the first bonding layer; and
a contact layer between the first-type semiconductor layer and the reflective structure;
wherein a critical angle at the first interface for a light emitted from the light-emitting stack is larger than that at the second interface.
2. The light-emitting device of claim 1 , wherein the reflective structure comprises a metal layer with a first side wall covered by the first bonding layer.
3. The light-emitting device of claim 2 , wherein the contact layer does not contact the metal layer.
4. The light-emitting device of claim 1 , wherein the bonding structure further comprising a second bonding layer between the first bonding layer and the substrate.
5. The light-emitting device of claim 4 , wherein the reflective structure comprises a metal layer with a first side wall and the second bonding layer does not cover the first side wall.
6. The light-emitting device of claim 2 , wherein the metal layer further comprises a second side wall and a bottom surface, and the second side wall and the bottom surface are covered by the first bonding layer.
7. The light-emitting device of claim 1 , wherein the bonding structure is connected to the reflective structure.
8. The light-emitting device of claim 2 , wherein the reflective structure further comprises a transparent conductive layer between the light-emitting stack and the metal layer.
9. The light-emitting device of claim 8 , wherein the transparent conductive layer has a first side surface covered by the first bonding layer.
10. The light-emitting device of claim 9 , wherein the transparent conductive layer further has a second side surface covered by the first bonding layer.
11. A light-emitting device, comprising:
a substrate;
a bonding structure on the substrate and comprising a first bonding layer;
a light-emitting stack on the bonding structure and having a first-type semiconductor layer, a second-type semiconductor layer, and an active layer between the first-type semiconductor layer and the second-type semiconductor layer;
a reflective structure between the first-type semiconductor layer and the substrate and comprising a metal layer and a transparent conductive layer between the first-type semiconductor layer and the metal layer; and
a void embedded within the first bonding layer; and
a contact layer between the first-type semiconductor layer and the reflective structure;
wherein the reflective structure directly connects to the light-emitting stack, the metal layer has a first side wall, a second side wall and a bottom surface, and the first side wall, the second side wall and the bottom surface are covered by and directly contact the first bonding layer.
12. The light-emitting device of claim 11 , wherein the metal layer comprises metal or alloy.
13. The light-emitting device of claim 11 , wherein the contact layer does not contact the metal layer.
14. The light-emitting device of claim 11 , further comprising a first electrode on the second-type semiconductor layer.
15. The light-emitting device of claim 14 , wherein the first electrode does not overlap with the void in a vertical direction.
16. The light-emitting device of claim 11 , wherein the transparent conductive layer has a first side surface and a second side surface, wherein the first side surface and the second side surface are covered by and directly contact the first bonding layer.
17. The light-emitting device of claim 14 , further comprising a second electrode under the substrate.
18. The light-emitting device of claim 11 , further comprising a second bonding layer between the first bonding layer and the substrate.
19. The light-emitting device of claim 11 , wherein the first bonding layer comprises a metal material or a glue material.
20. A light-emitting module, comprising;
a carrier; and
a plurality of light-emitting units on the carrier;
wherein one of the light-emitting units is the light-emitting device of claim 1 .