Light-emitting device
A light-emitting device is provided. The light-emitting device comprises: an epitaxial structure comprising a first DBR stack, a light-emitting stack and a second DBR stack and a contact layer in sequence; an electrode on the epitaxial structure; a current blocking layer between the contact layer and the electrode; a first opening formed in the current blocking layer; and a second opening formed in the electrode and within the first opening; wherein a part of the electrode fills in the first opening and contacts the contact layer.
1. A light-emitting device comprising:
an epitaxial structure comprising a first DBR stack, a light-emitting stack and a second DBR stack and a contact layer in sequence;
an electrode on the epitaxial structure;
a current blocking layer between the contact layer and the electrode;
a first opening formed in the current blocking layer; and
a second opening formed in the electrode and within the first opening;
wherein a part of the electrode fills in the first opening and contacts the contact layer.
2. The light-emitting device according to claim 1 , further comprising a substrate under the epitaxial structure, wherein the substrate has a first width, the epitaxial structure comprises a ridge having a width smaller than the first width of the substrate and comprises an exposed mesa wall, and the current blocking layer covers the exposed mesa wall.
3. The light-emitting device according to claim 2 , wherein the electrode covers the exposed mesa wall, and wherein the current blocking layer is between the exposed mesa wall and the electrode.
4. The light-emitting device according to claim 1 , wherein each layer of the second DBR stack consists essentially of a Group III-V semiconductor material.
5. The light-emitting device according to claim 1 , wherein the conductivity of a portion of the second DBR stack right under the first opening is substantially the same as the conductivity of the other portion of the second DBR stack covered by the current blocking layer.
6. The light-emitting device according to claim 1 , wherein the first opening has a first maximum width, and the second opening exposes the contact layer and has a second maximum width less than the first maximum width.
7. The light-emitting device according to claim 1 , wherein the current blocking layer comprises an inner part and an outer part separated from the inner part.
8. The light-emitting device according to claim 7 , wherein the electrode covers along a side wall of the inner part of the current blocking layer in the first opening and is on a periphery part of the inner part of the current blocking layer.
9. The light-emitting device according to claim 8 , wherein the second opening exposes a part of the inner part of the current blocking layer.
10. The light-emitting device according to claim 1 , further comprising a growth substrate on which the epitaxial structure is epitaxially grown.
11. The light-emitting device according to claim 1 , wherein the light-emitting device is devoid of an oxidized layer and an ion implanted layer in the second DBR stack.
12. The light-emitting device according to claim 1 , wherein the number of the first opening is more than one, and the first openings are arranged in a two-dimensional array in the current blocking layer and separated from one another.
13. The light-emitting device according to claim 12 , wherein the current blocking layer is a contiguous layer.
14. The light-emitting device according to claim 12 , wherein the number of the second opening is more than one, and the second openings are arranged in a two-dimensional array in the electrode and separated from one another, and each of the second openings is correspondingly formed within one of the first openings.
15. The light-emitting device according to claim 14 , wherein the electrode is a contiguous layer.
16. The light-emitting device according to claim 1 , wherein the electrode covers a side wall of the current blocking layer enclosing the first opening.
17. The light-emitting device according to claim 16 , wherein the electrode covers more than 50% of a surface area of the current blocking layer.
18. The light-emitting device according to claim 1 , wherein the electrode is separated from a side wall of the current blocking layer enclosing the first opening.
19. The light-emitting device according to claim 18 , wherein the electrode covers less than 50% of a surface area of the current blocking layer.
20. The light-emitting device according to claim 1 , wherein the current blocking layer has a thickness substantially equals to nλ/4, wherein λ is the peak wavelength of the radiation emitted from the light-emitting stack, and n is an odd positive integer.