Light emitting diode

1. A light emitting diode, comprising:

a substrate;

an n-type semiconductor layer, an active layer, and a p-type semiconductor layer arranged on the substrate;

a transparent electrode layer arranged on and in contact with the p-type semiconductor layer, the transparent electrode layer comprising an opening exposing the p-type semiconductor layer;

a current blocking portion arranged in the opening; and

an electrode pad arranged on the current blocking portion.

2. The light emitting diode of claim 1 , wherein the current blocking portion comprises SiO 2 , Al 2 O 3 , Si 3 N 4 , and/or TiO 2 .

3. The light emitting diode of claim 1 , wherein the current blocking portion comprises a distributed Bragg reflector (DBR).

4. The light emitting diode of claim 3 , wherein the DBR comprises a higher light reflectivity than the electrode pad.

5. The light emitting diode of claim 3 , wherein the DBR comprises a plurality of low-refractivity layers and high-refractivity layers alternately stacked, the low refractivity layers comprising SiO 2 or Al 2 O 3 and the high refractivity layers comprising Si 3 N 4 or TiO 2 .

6. The light emitting diode of claim 1 , wherein the electrode pad extends into the opening of the transparent electrode layer.

7. The light emitting diode of claim 6 , wherein the electrode pad is arranged directly on an upper surface of the transparent electrode layer outside of the opening.

8. The light emitting diode of claim 5 , wherein one of the low-refractivity layers directly contacts the p-type semiconductor layer.

9. The light emitting diode of claim 5 , wherein one of the high-refractivity layers directly contacts the electrode pad.

10. The light emitting diode of claim 5 , wherein a first thickness is represented by the formula t 1 =mλ/4n l , wherein m comprises an odd number, λ comprises a wavelength of light, and n l comprises a refractive index of the low-refractivity layers,

wherein a second thickness is represented by the formula t 2 =mλ/4n h , wherein m comprises the odd number, λ comprises the wavelength of light, and n h comprises a refractive index of the high-refractivity layers,

wherein the low-refractivity layers comprise the first thickness and the high-refractivity layers comprise the second thickness, and

wherein the DBR comprises a reflectance of at least 95% in light comprising the wavelength λ.

11. The light emitting device of claim 10 , wherein the wavelength λ corresponds to the peak emission wavelength of the active layer.

12. The light emitting device of claim 3 , wherein the DBR blocks current from directly flowing between the electrode pad and the p-type semiconductor layer.

13. The light emitting device of claim 1 , further comprising a lower DBR interposed between the active layer and the substrate.

14. The light emitting device of claim 13 , wherein the lower DBR comprises a plurality of low-refractivity layers and high-refractivity layers alternately stacked.

15. The light emitting device of claim 13 , wherein light emitted by the active layer and/or reflected by the current blocking layer is reflected toward the transparent electrode layer by the lower DBR.

16. A light emitting diode, comprising:

a substrate;

an n-type semiconductor layer, an active layer, and a p-type semiconductor layer arranged on the substrate;

a transparent electrode layer arranged on the p-type semiconductor layer, the transparent electrode layer comprising an opening exposing the p-type semiconductor layer;

a current blocking portion arranged in the opening; and

an electrode pad arranged on the current blocking portion,

wherein the current blocking portion comprises a distributed Bragg reflector (DBR) comprising a plurality of low-refractivity layers and high-refractivity layers alternately stacked, the low refractivity layers comprising SiO 2 or Al 2 O 3 and the high refractivity layers comprising Si 3 N 4 or TiO 2 ,

wherein the low-refractivity layers comprise a first thickness, and the high-refractivity layers comprise a second thickness, the first thickness being represented by the formula t 1 =mλ/4n l , wherein m comprises an odd number, λ comprises a wavelength of light, and n l comprises a refractive index of the low-refractivity layers, and the second thickness being represented by the formula t 2 =mλ/4n h , wherein m comprises the odd number, λ comprises the wavelength of light, and n h comprises a refractive index of the high-refractivity layers, and

wherein the DBR comprises a reflectance of at least 95% in light comprising the wavelength λ.

17. The light emitting device of claim 16 , further comprising a tunnel layer interposed between the p-type semiconductor layer and the transparent electrode layer.