Vertical light emitting device having a photonic crystal structure
View Patent ↗A light emitting device having a vertical structure and a method for manufacturing the same, which are capable of increasing light extraction efficiency, are disclosed. The method includes forming a light extraction layer on a substrate, forming a plurality of semiconductor layers on the light extraction layer, forming a first electrode on the semiconductor layers, forming a support layer on the first electrode, removing the substrate, and forming a second electrode on a surface from which the substrate is removed.
1. A light emitting device having a vertical structure, comprising:
a conductive support layer;
a first electrode located over the conductive support layer;
a plurality of semiconductor layers located over the first electrode;
a photonic crystal layer located over the semiconductor layers, the photonic crystal layer being formed with a plurality of holes arranged periodically;
a second electrode located over the photonic crystal layer;
a reflective layer located between the photonic crystal layer and the second electrode;
a transparent ohmic layer located between the photonic crystal layer and the second electrode;
wherein the reflective layer is located between the transparent ohmic layer and the second electrode.
2. The light emitting device according to claim 1 , wherein dielectric material is filled at least in a portion of the photonic crystal layer, on which the second electrode is formed.
3. The light emitting device according to claim 2 , wherein the dielectric material is either silicon dioxide or silicon nitride.
4. The light emitting device according to claim 1 , wherein the holes of the photonic crystal layer have a depth of 0.05 to 10 μm.
5. The light emitting device according to claim 1 , wherein the holes of the photonic crystal layer have a radius of 0.01 to 6 μm.
6. The light emitting device according to claim 1 , wherein the photonic crystal layer has a period of 0.03 to 18 μm.
7. The light emitting device according to claim 1 , wherein the semiconductor layers include:
a p-type GaN layer located on the first electrode;
a light emitting layer located on the p-type GaN layer; and
an n-type GaN layer located on the light emitting layer.
8. The light emitting device according to claim 1 , wherein the conductive support layer is configured as a metal plate comprising material selected from the group consisting of copper, gold, nickel, and an alloy thereof, or as a semiconductor substrate.
9. The light emitting device according to claim 1 , further comprising: an additional layer located between the second electrode and the conductive support layer.
10. The light emitting device according to claim 9 , wherein the additional layer is an n-type GaN layer.
11. The light emitting device according to claim 1 , wherein the second electrode comprises material selected from the group consisting of ITO, ZnO, AlZnO, InZnO, and a combination thereof.
12. The light emitting device according to claim 1 , further comprising:
a reflective electrode located between the conductive support layer and the first electrode.
13. The light emitting device according to claim 1 , wherein the transparent ohmic layer is covering at least a portion of the photonic crystal layer.
14. The light emitting device according to claim 1 , further comprising a seed metal between the support layer and the first electrode.