Light emitting device with electrode having plurality of adhesive seeds spaced from one another on the light emitting structure
Disclosed is a light emitting device including a light emitting structure including a first conductive-type semiconductor layer, a second conductive-type semiconductor layer and an active layer interposed between the first conductive-type semiconductor layer and the second conductive-type semiconductor layer, a first electrode layer electrically connected to the first conductive-type semiconductor layer, and a second electrode layer disposed on the second conductive-type semiconductor layer, wherein the second electrode layer includes a plurality of adhesive seeds spaced from one another on the light emitting structure, a reflective layer disposed on the plurality of adhesive seeds, and a protective layer disposed on the reflective layer, wherein the reflective layer contains silver (Ag) or an Ag alloy. As a result, it is possible to improve light reflectance and electrical properties of the electrode layer of the light emitting device and reliability of the electrode layer.
1. A light emitting device comprising:
a light emitting structure including a first conductive-type semiconductor layer, a second conductive-type semiconductor layer and an active layer interposed between the first conductive-type semiconductor layer and the second conductive-type semiconductor layer;
a first electrode layer electrically connected to the first conductive-type semiconductor layer; and
a second electrode layer disposed on the second conductive-type semiconductor layer,
wherein the second electrode layer includes:
a plurality of adhesive seeds spaced from one another on the light emitting structure;
a reflective layer disposed on the plurality of adhesive seeds; and
a protective layer disposed on the reflective layer,
wherein the reflective layer contains silver (Ag) or an Ag alloy.
2. The light emitting device according to claim 1 , wherein the first electrode layer is disposed on the upper surface of the first conductive-type semiconductor layer of which the upper surface is partially exposed,
the first electrode layer includes:
a plurality of adhesive seeds spaced from one another on the light emitting structure;
a reflective layer disposed on the adhesive seeds; and
a protective layer disposed on the reflective layer,
wherein the reflective layer contains silver (Ag) or an Ag alloy.
3. The light emitting device according to claim 1 , wherein the reflective layer contacts the light emitting structure.
4. The light emitting device according to claim 1 , wherein a thickness of the reflective layer is larger than a thickness of the adhesive seed.
5. The light emitting device according to claim 1 , wherein the thickness of the reflective layer is 10 nm to 20 nm.
6. The light emitting device according to claim 1 , wherein the Ag alloy contains silver and at least one of Cu, Re, Bi, Al, Zn, W, Sn, In and Ni.
7. The light emitting device according to claim 1 , wherein a thickness of the adhesive seed is 1 nm to 10 nm.
8. The light emitting device according to claim 1 , wherein a pitch between the adhesive seeds is 0.5- to 2-fold a width of the adhesive seed.
9. The light emitting device according to claim 1 , wherein the adhesive seeds contain a solid solution.
10. The light emitting device according to claim 1 , wherein the reflective layer includes a plurality of seeds distributed therein.
11. The light emitting device according to claim 1 , wherein the first conductive-type semiconductor layer is an n-type semiconductor layer and the first conductive-type semiconductor layer and the first electrode layer constitute an ohmic contact.
12. The light emitting device according to claim 1 , wherein the adhesive seeds or seeds contain at least one of Cr, Ti, V, Ta and Al.
13. The light emitting device according to claim 1 , wherein the protective layer contains at least one of Cr, Ti, Ni, Pd, Pt, W, Co, and Cu.
14. The light emitting device according to claim 1 , further comprising a wire bonding layer disposed on the protective layer.
15. The light emitting device according to claim 2 , further comprising:
a light transmitting layer disposed on the second conductive-type semiconductor layer,
wherein the second electrode layer is disposed on the light transmitting layer.
16. The light emitting device according to claim 1 , wherein the second conductive-type semiconductor layer and the second electrode layer constitute a schottky junction.
17. A light emitting device package including a light emitting device, comprising:
wherein the light emitting device includes:
a light emitting structure including a first conductive-type semiconductor layer, a second conductive-type semiconductor layer and an active layer interposed between the first conductive-type semiconductor layer and the second conductive-type semiconductor layer;
a first electrode layer electrically connected to the first conductive-type semiconductor layer; and
a second electrode layer disposed on the second conductive-type semiconductor layer,
wherein the second electrode layer includes:
a plurality of adhesive seeds spaced from one another on the light emitting structure;
a reflective layer disposed on the adhesive seeds; and
a protective layer disposed on the reflective layer,
wherein the reflective layer contains silver (Ag) or an Ag alloy.
18. A lighting device including a light emitting device, comprising:
wherein the light emitting device includes:
a light emitting structure including a first conductive-type semiconductor layer, a second conductive-type semiconductor layer and an active layer interposed between the first conductive-type semiconductor layer and the second conductive-type semiconductor layer;
a first electrode layer electrically connected to the first conductive-type semiconductor layer; and
a second electrode layer disposed on the second conductive-type semiconductor layer,
wherein the second electrode layer includes:
a plurality of adhesive seeds spaced from one another on the light emitting structure;
a reflective layer disposed on the plurality of adhesive seeds; and
a protective layer disposed on the reflective layer,
wherein the reflective layer contains silver (Ag) or an Ag alloy.
19. The light emitting device according to claim 2 , wherein the adhesive seeds or seeds contain at least one of Cr, Ti, V, Ta and Al.
20. The light emitting device according to claim 10 , wherein the adhesive seeds or seeds contain at least one of Cr, Ti, V, Ta and Al.