Group III nitride nanorod light emitting device

1. A group III nitride nanorod light emitting device, comprising:

a substrate;

an insulating film disposed on the substrate, and including a plurality of openings exposing parts of the substrate and having different diameters; and

a plurality of first conductive group III nitride nanorods having different diameters, respectively disposed in the plurality of openings, respective diameters of the plurality of first conductive group III nitride nanorods being greater than or equal to 120 nm but less than 1 μm, wherein:

each first conductive group III nitride nanorod of the plurality of first conductive group III nitride nanorods has an active layer and a second conductive semiconductor layer sequentially disposed on a surface of the active layer,

the plurality of first conductive group III nitride nanorods include a first group on a first area of the substrate and a second group on a second area of the substrate different from the first area, each group including two or more first conductive group III nitride nanorods that have an identical diameter and an identical height, and

the diameter of the nanorods of the first group is smaller than the diameter of the nanorods of the second group.

2. The group III nitride nanorod light emitting device of claim 1 , wherein the insulating film includes a plurality of groups, each including a plurality of openings having the same diameter, and the plurality of groups have different diameters.

3. The group III nitride nanorod light emitting device of claim 1 , wherein the active layer includes at least a pair of a quantum barrier layer and a quantum well layer.

4. The group III nitride nanorod light emitting device of claim 3 , wherein the quantum barrier layer is formed of Al y Ga 1-y N (0≦y≦1), and the quantum well layer is formed of In x Ga 1-x N (0≦x≦1).

5. The group III nitride nanorod light emitting device of claim 3 , wherein the active layer of one of the plurality of first conductive group III nitride nanorods has a content of indium (In) less than a content of 1n of the active layer of another one of the plurality of first conductive group III nitride nanorod having a smaller diameter than a diameter of said one of the plurality of first conductive group III nitride nanorods.

6. The group III nitride nanorod light emitting device of claim 1 , wherein the light emitting device including the plurality of first conductive group III nitride nanorods having the different diameters is configured to emit light of different wavelengths.

7. The group III nitride nanorod light emitting device of claim 1 , the substrate comprises a material selected from the group consisting of a sapphire, silicon (Si), zinc oxide (ZnO), gallium arsenide (GaAs), silicon carbide (SiC), MgAl 2 O 4 , magnesium oxide (MgO), lithium aluminate (LiAlO 2 ), LiGaO 2 and gallium nitride (GaN).

8. The group III nitride nanorod light emitting device of claim 1 , wherein the substrate is a sapphire substrate having a C(0001)-plane, an A(1120)-plane, or an R(1102)-plane.

9. The group III nitride nanorod light emitting device of claim 1 , wherein the insulating film includes a silicon oxide, a silicon nitride or a titanium dioxide.

10. The group III nitride nanorod light emitting device of claim 1 , wherein the insulating film has a thickness of 50 nm to 100 nm.

11. The group III nitride nanorod light emitting device of claim 1 , wherein the openings have a shape of a quadrangle, a hexagon or a circular.

12. The group III nitride nanorod light emitting device of claim 1 , wherein the plurality of first conductive group III nitride nanorods have different diameters that are proportional to diameters of the openings.

13. The group III nitride nanorod light emitting device of claim 12 , wherein the plurality of first conductive group III nitride nanorods have diameters greater than diameters of the openings in which the plurality of first conductive group III nitride nanorods are disposed.

14. The group III nitride nanorod light emitting device of claim 1 , wherein the second conductive semiconductor layers have a thickness of 20 nm or more.

15. The group III nitride nanorod light emitting device of claim 1 , wherein:

the plurality of openings are divided into a first, a second and a third groups, each including at least two openings having substantially equal diameters, and

openings of at least two of the first, second and third groups have different diameters from each other.

16. The group III nitride nanorod light emitting device of claim 1 , wherein:

the plurality of first conductive group III nitride nanorods are divided into a first, a second and a third groups, each including at least two first conductive group III nitride nanorods having the same diameter, and

openings of at least two of the first, second and third groups having different diameters from each other.

17. A group III nitride nanorod emitting device, comprising:

a substrate;

a buffer layer;

an insulating film disposed on the buffer layer, and including a plurality of openings exposing parts of the buffer layer and having different diameters;

a plurality of light emitting structures disposed on the plurality of openings, respectively, and having a plurality of first conductive group III nitride nanorods that have different diameters, each of the light emitting structures having first conductive group III nitride nanorod of the plurality of first conductive group III nitride nanorods disposed on the exposed part of the buffer layer, and an active layer and a second conductive semiconductor layer sequentially disposed on a surface of the first conductive group III nitride nanorod, wherein:

respective diameters of the plurality of first conductive group III nitride nanorods are greater than or equal to 120 nm but less than 1 μm,

the plurality of light emitting structures include a first group on a first area of the substrate and a second group on a second area of the substrate, each group including two or more light emitting structures that have the active layers having an identical content of indium (In) on an identical crystal plane, and

the active layer of the first group has a different content of In from an In content of the active layer of the second group on the same crystal plane as a crystal plane of the first group.

18. The group III nitride nanorod light emitting device of claim 17 , wherein:

the plurality of light emitting structures are divided into a plurality of groups,

the light emitting structures in each of at least two of the plurality of groups have an identical diameter, and

the light emitting structures in one group have a different diameter from a diameter of the light emitting structures in another group.

19. The group III nitride nanorod light emitting device of claim 18 , wherein:

the plurality of light emitting structures are divided into a plurality of groups,

distances between adjacent light emitting structures in each of at least two of the plurality of groups are equal, and

a distance between adjacent light emitting structures in one group is different from a distance between adjacent light emitting structures in the other group.

20. The group III nitride nanorod light emitting device of claim 17 , wherein:

the plurality of light emitting structures are divided into a plurality of groups,

the light emitting structures in each of at least two of the plurality of groups have an identical height, and

the light emitting structures in one group have a different height from a height of the light emitting structures in another group.