Nanostructure semiconductor light-emitting device
A nanostructure semiconductor light-emitting device includes a base layer formed of a first conductivity-type semiconductor, a first material layer disposed on the base layer and including a plurality of openings, a plurality of light-emitting nanostructures, each of which extends through each of the plurality of openings and includes a nanocore formed of a first conductivity-type semiconductor, an active layer and a second conductivity-type semiconductor shell layer, sequentially disposed on the nanocore, a filling layer disposed on the first material layer, wherein the filling layer fills spaces between the plurality of light-emitting nanostructures and a portion of each of the plurality of light-emitting nanostructures is exposed by the filling layer, a second conductivity-type semiconductor extension layer disposed on the filling layer and covering the exposed portion of each of the plurality of light-emitting nanostructures, and a contact electrode layer disposed on the second conductivity-type semiconductor extension layer.
1. A nanostructure semiconductor light-emitting device, comprising:
a base layer formed of a first conductivity-type semiconductor;
a first material layer disposed on the base layer and including a plurality of openings;
a plurality of light-emitting nanostructures, each of which extends through each of the plurality of openings and includes a nanocore formed of a first conductivity-type semiconductor, an active layer and a second conductivity-type semiconductor shell layer, sequentially disposed on the nanocore;
a filling layer disposed on the first material layer, wherein the filling layer fills spaces between the plurality of light-emitting nanostructures and a portion of each of the plurality of light-emitting nanostructures is exposed by the filling layer;
a second conductivity-type semiconductor extension layer disposed on the filling layer and covering the exposed portion of each of the plurality of light-emitting nanostructures; and
a contact electrode layer disposed on the second conductivity-type semiconductor extension layer.
2. The nanostructure semiconductor light-emitting device of claim 1 , wherein each of the plurality of light-emitting nanostructures comprises a body having a first crystal plane and a tip having a second crystal plane different from the first crystal plane.
3. The nanostructure semiconductor light-emitting device of claim 2 , wherein the exposed portion of each of the plurality of light-emitting nanostructures includes at least the tip of each of the plurality of light-emitting nanostructures.
4. The nanostructure semiconductor light-emitting device of claim 2 , wherein a height of the filling layer is greater than about 50% of a height of the body of each of the plurality of light-emitting nanostructures.
5. The nanostructure semiconductor light-emitting device of claim 1 , further comprising a reflective metal layer disposed on the contact electrode layer.
6. The nanostructure semiconductor light-emitting device of claim 5 , wherein a lower surface of the reflective metal layer is planar.
7. The nanostructure semiconductor light-emitting device of claim 1 , further comprising an omnidirectional reflector disposed on the contact electrode layer.
8. The nanostructure semiconductor light-emitting device of claim 7 , wherein an upper surface of the second conductivity-type semiconductor extension layer is not planar and an upper surface of the omnidirectional reflector is formed according to a shape of the upper surface of the second conductivity-type semiconductor extension layer.
9. The nanostructure semiconductor light-emitting device of claim 7 , wherein the omnidirectional reflector includes first and second refraction layers having different refractive indices.
10. The nanostructure semiconductor light-emitting device of claim 1 , wherein portions of the second conductivity-type semiconductor extension layer corresponding to each of the plurality of light-emitting nanostructures are connected to each other.
11. The nanostructure semiconductor light-emitting device of claim 10 , wherein an upper surface of the second conductivity-type semiconductor extension layer is planar.
12. The nanostructure semiconductor light-emitting device of claim 1 , further comprising:
a first electrode disposed on a portion of an upper surface of the contact electrode layer;
and a second electrode disposed on a portion of one of an upper surface and a lower surface of the base layer.
13. The nanostructure semiconductor light-emitting device of claim 1 , wherein a plurality of protrusions are formed on a lower surface of the base layer.
14. The nanostructure semiconductor light-emitting device of claim 1 , further comprising a graded refractive index layer disposed on a lower surface of the base layer, wherein the graded refractive index layer comprises a plurality of layers having refractive indices gradually decreasing away from the lower surface of the base layer.
15. The nanostructure semiconductor light-emitting device of claim 1 , further comprising a growth substrate disposed on the base layer, wherein an upper surface of the growth substrate has a plurality of protrusions.
16. The nanostructure semiconductor light-emitting device of claim 1 , wherein the contact electrode layer is in direct contact with the filling layer.
17. A nanostructure semiconductor light-emitting device, comprising:
a base layer formed of a first conductivity-type semiconductor;
a first material layer disposed on the base layer and including a plurality of openings;
a plurality of nanostructures extending through each of the plurality of openings, wherein each of the plurality of nanostructures includes a nanocore formed of a first conductivity-type semiconductor and an active layer disposed on the nanocore;
a second conductivity-type semiconductor layer including a plurality of shell layers, each of which surrounds each of the plurality of nanostructures, and an extension layer connecting each of the plurality of shell layers; and
a contact electrode layer disposed on the second conductivity-type semiconductor layer.
18. A nanostructure semiconductor light-emitting device, comprising:
a base layer formed of a first conductivity-type semiconductor;
a first material layer disposed on the base layer and including a plurality of openings;
a plurality of light-emitting nanostructures protruding from the base layer and extending through the plurality of openings;
a filling layer disposed on the first material layer and filling spaces between the plurality of light-emitting nanostructures, a portion of each of the plurality of light-emitting nanostructures exposed by the filling layer;
a second conductivity-type semiconductor extension layer disposed on the filling layer and covering the exposed portion of each of the plurality of light-emitting nanostructures, an upper surface of the second conductivity-type semiconductor extension layer being uneven; and
a contact electrode layer disposed on the second conductivity-type semiconductor extension layer.
19. The nanostructure semiconductor light-emitting device of claim 18 , wherein the upper surface of the second conductivity-type semiconductor extension layer at an area over the plurality of light-emitting nanostructures has a level higher than that of an area excluding the area over the plurality of light-emitting nanostructures.
20. The nanostructure semiconductor light-emitting device of claim 18 , further comprising an omnidirectional reflector disposed on the contact electrode layer.