Light emitting device and method of fabricating the same
Provided are a light emitting device and a method of fabricating the same. The light emitting device includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer, the active layer being formed of a semiconductor material. Also, the light emitting device further includes a current spreading layer comprising a plurality of carbon nanotube bundles physically connected to each other on one of the first and second conductive type semiconductor layers.
1. A light emitting device comprising:
a first conductive type semiconductor layer;
a second conductive type semiconductor layer;
an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer, the active layer being formed of a semiconductor material;
a current spreading layer on one of the first and second conductive type semiconductor layers, the current spreading layer comprising a plurality of sets of carbon nanotube bundles physically connected to each other;
a first electrode layer disposed on an other one of the first and second conductive type semiconductor layers;
a second electrode layer disposed on a top surface of the current spreading layer;
a transparent conductive layer disposed between the top surface of the current spreading layer and a bottom surface of the second electrode layer; and
a reflection member contacted between the transparent conductive layer and the second electrode layer,
wherein the transparent conductive layer has a material different from the current spreading layer and includes a non-metallic material.
2. The light emitting device according to claim 1 , wherein the current spreading layer has a network structure in which the plurality of sets of carbon nanotube bundles are connected to each other.
3. The light emitting device according to claim 2 , wherein the current spreading layer physically contacts a top surface of the second conductive type semiconductor layer and a bottom surface of the transparent conductive layer, and
wherein the second conductive type semiconductor layer includes a p-type dopant.
4. The light emitting device according to claim 2 , wherein the plurality of sets of carbon nanotube bundles each has a structure in which a plurality of single-walled carbon nanotubes are tied up together with each other.
5. The light emitting device according to claim 1 , wherein the plurality of sets of carbon nanotube bundles each has a density ranging from about 30% to about 90% of an area of one of the first and second conductive type semiconductor layers.
6. The light emitting device according to claim 1 , wherein the current spreading layer has a thickness of about 10 nm to about 70 nm.
7. The light emitting device according to claim 1 , wherein the current spreading layer surface-contacts one of the first and second conductive type semiconductor layers.
8. The light emitting device according to claim 1 , wherein the current spreading layer has the same area as an area of one of the first and second conductive type semiconductor layers.
9. The light emitting device according to claim 1 , further comprising a support member having conductivity on a top surface of the reflection member.
10. The light emitting device according to claim 9 , wherein each of the second electrode layer, the reflection member, and the current spreading layer has the same area as an area of one of the first and second conductive type semiconductor layers.
11. The light emitting device according to claim 1 , wherein the current spreading layer includes at least one of an optical transmittance layer or a metallic layer, and
wherein the transparent conductive layer includes a conductive oxide material.
12. The light emitting device according to claim 1 , wherein the current spreading layer has a conductivity greater than a conductivity of one of the first and second conductive type semiconductor layers.
13. The light emitting device according to claim 1 , wherein the current spreading layer physically contacts a top surface of one of the first and second conductive type semiconductor layers and the transparent conductive layer.
14. A light emitting device comprising:
a first conductive type semiconductor layer;
a second conductive type semiconductor layer;
an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer, the active layer being formed of a semiconductor material;
a current spreading layer contacting a top surface of the second conductive type semiconductor layer and in which a plurality of sets of carbon nanotube bundles are connected to each other through a network, the plurality of sets of carbon nanotube bundles each comprising a plurality of single-walled carbon nanotubes;
an electrode layer disposed on a top surface of the current spreading layer; and
a conductive layer disposed between the top surface of the current spreading layer and a bottom surface of the electrode layer,
wherein the conductive layer has a material different from the current spreading layer and physically contacts the top surface of the current spreading layer,
wherein the conductive layer includes a non-metallic material,
wherein the conductive layer includes a transparent conductive layer, and
wherein the electrode layer includes a reflection layer and a conductive support member on the reflection layer.
15. The light emitting device according to claim 14 , wherein the plurality of sets of carbon nanotube bundles each has a density ranging from about 30% to about 90% of an area of the second conductive type semiconductor layer.
16. The light emitting device according to claim 14 , wherein the current spreading layer has a thickness of about 10 nm to about 70 nm.
17. The light emitting device according to claim 14 , wherein the current spreading layer has the same area as an area of the second conductive type semiconductor layer.