GaN-based compound semiconductor light emitting device

1. A semiconductor light emitting device comprising:

a substrate;

an n-type semiconductor layer formed on the substrate;

an active layer formed on a first region of the n-type semiconductor layer;

a p-type semiconductor layer formed on the active layer;

a p-type electrode formed on the p-type semiconductor layer;

an n-type electrode formed on a second region of the n-type semiconductor layer separated from the first region of the n-type semiconductor layer;

a single dielectric layer formed on a sidewall of a stack comprising the p-type semiconductor layer, the active layer, and the n-type semiconductor layer; and

a reflective layer formed on the single dielectric layer,

wherein a refractive index of the single dielectric layer is 1 to 2.5,

wherein a thickness of the single dielectric layer is ¼ the wavelength of light emitted from the active layer,

wherein the single dielectric layer and the reflective layer constitute an omnidirectional reflective contract having a predetermined degree of reflectivity regardless of a wavelength of light emitted from the active layer and an angle of the light incident on the sidewall of the stack, and

wherein the sidewall of the stack is disposed at an angle of approximately 35 to 55 degrees relative to a plane of the substrate.

2. The semiconductor light emitting device of claim 1 , wherein the single dielectric layer is formed of a material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, lithium fluoride, and calcium fluoride, and magnesium fluoride.

3. The semiconductor light emitting device of claim 1 , wherein the substrate is formed of a transparent material.

4. The semiconductor light emitting device of claim 3 , wherein the substrate is formed of sapphire.

5. The semiconductor light emitting device of claim 1 , wherein the reflective layer is formed of a material selected from the group consisting of Ag, Al, Au, Pt, Ru, and Ir.

6. The semiconductor light emitting device of claim 1 , wherein the n-type semiconductor layer, the active layer, and the p-type semiconductor layer are GaN-based group III-V nitride compounds.

7. The semiconductor light emitting device of claim 1 , wherein the single dielectric layer is formed on the first region of the n-type semiconductor layer on which the active layer is formed.

8. The semiconductor light emitting device of claim 1 , wherein the reflective layer formed on the single dielectric layer is configured to reflect the light emitted from the active layer toward the substrate.

9. The semiconductor light emitting device of claim 1 , wherein the p-type electrode formed on the p-type semiconductor layer is configured to reflect light emitted from the active layer toward the substrate.

10. The semiconductor light emitting device of claim 1 , wherein the reflective layer is connected to the p-type electrode formed on the p-type semiconductor layer.

11. The semiconductor light emitting device of claim 1 , wherein the reflective layer is connected to the n-type electrode formed on the second region of the n-type semiconductor layer.

12. The semiconductor light emitting device of claim 3 , wherein the substrate is configured to transmit the light emitted from the active layer and light reflected from the reflective layer therethrough.

13. The semiconductor light emitting device of claim 3 , wherein the substrate is configured to transmit the light emitted from the active layer, light reflected for the reflective layer, and light reflected from the p-electrode therethrough.

14. The semiconductor light emitting device of claim 1 , wherein the reflectivity of the omnidirectional reflective contact is approximately 84 to 94%.