Light emitting device and display apparatus including the same
A light emitting device including a first light emitting cell, a second light emitting cell, and a third light emitting cell each including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, pads electrically connected to the first, second, and third light emitting cells, a first wavelength converter configured to convert a wavelength of light emitted from the first light emitting cell into a first wavelength, and a second wavelength converter configured to convert a wavelength of light emitted from the second light emitting cell into a second wavelength longer than the first wavelength, in which the first light emitting cell has a larger area than the third light emitting cell, and the second light emitting cell has a larger area than the first light emitting cell.
1. A light emitting device comprising:
a first light emitting cell, a second light emitting cell, and a third light emitting cell each including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer;
pads electrically connected to the first, second, and third light emitting cells;
a first wavelength converter configured to convert a wavelength of light emitted from the first light emitting cell into a first wavelength; and
a second wavelength converter configured to convert a wavelength of light emitted from the second light emitting cell into a second wavelength longer than the first wavelength,
wherein side surfaces of the first wavelength converter are flush with side surfaces of the first light emitting cell, respectively,
wherein side surfaces of the second wavelength converter are flush with side surfaces of the second light emitting cell, respectively,
wherein the first light emitting cell has a larger area than the third light emitting cell, and the second light emitting cell has a larger area than the first light emitting cell, and
wherein a distance between the first light emitting cell and the second light emitting cell is equal to a distance between the second light emitting cell and the third light emitting cell.
2. The light emitting device of claim 1 , wherein:
each of the first, second, and third light emitting cells is configured to emit blue light;
light having the first wavelength is green light; and
light having the second wavelength is red light.
3. The light emitting device of claim 2 , wherein area ratios of the first light emitting cell and the second light emitting cell with regard to the third light emitting cell are inversely proportional to light conversion efficiency of the first wavelength converter and light conversion efficiency of the second wavelength converter, respectively.
4. The light emitting device of claim 1 , further comprising a third wavelength converter configured to convert a wavelength of light emitted from the third light emitting cell into a third wavelength shorter than the first wavelength,
wherein the first, second, and third light emitting cells are configured to emit ultraviolet light.
5. The light emitting device of claim 4 , wherein:
light having the first wavelength is green light;
light having the second wavelength is red light; and
light having the third wavelength is blue light.
6. The light emitting device of claim 5 , wherein area ratios of the first light emitting cell and the second light emitting cell with regard to the third light emitting cell are inversely proportional to a light conversion efficiency ratio of the first wavelength converter and a light conversion efficiency ratio of the second wavelength converter with regard to the third wavelength converter, respectively.
7. The light emitting device of claim 4 , further comprising:
a first color filter disposed on the first wavelength converter;
a second color filter disposed on the second wavelength converter; and
a third color filter disposed on the third wavelength converter.
8. The light emitting device of claim 1 , further comprising:
a first color filter disposed on the first wavelength converter; and
a second color filter disposed on the second wavelength converter.
9. The light emitting device of claim 1 , further comprising a substrate on which the first, second, and third light emitting cells are disposed.
10. The light emitting device of claim 9 , further comprising partition walls disposed between each of the first, second, and third light emitting cells and configured to not transmit light,
wherein:
a height of each of the first, second, and third light emitting cells is lower than a height of each partition wall; and
a distance between the partition walls and the first, second, and third light emitting cells is less than about 20 μm.
11. The light emitting device of claim 10 , wherein the partition walls provided between the first light emitting cell, the second light emitting cell, and the third light emitting cell are integrally connected to each other.
12. The light emitting device of claim 10 , wherein a width of each partition wall increases as the partition wall is disposed further away from the substrate.
13. The light emitting device of claim 10 , wherein a ratio of an area occupied by the partition walls in a planar area of the substrate is 0.5 to 0.99.
14. The light emitting device of claim 10 , wherein a height of each partition wall is in a range of about 15 μm to about 115 μm.
15. The light emitting device of claim 9 , wherein
the first, second, and third light emitting cells are configured to emit green light, red light, and blue light, respectively.
16. The light emitting device of claim 15 , wherein the distance between the first light emitting cell and the second light emitting cell is different from a distance between the first light emitting cell and the third light emitting cell.
17. The light emitting device of claim 16 , wherein:
the first, second, and third light emitting cells are provided in one pixel; and a distance between the second and third light emitting cells provided in the one pixel is shorter than a distance between the second light emitting cell and any one of the light emitting cells provided in an adjacent pixel.
18. The light emitting device of claim 9 , wherein the first, second, and third light emitting cells are arranged in substantially a triangular shape.
19. The light emitting device of claim 9 , wherein the first, second, and third light emitting cells are arranged along a straight line.
20. The light emitting device of claim 9 , wherein the first conductivity type semiconductor layers of the first, second, and third light emitting cells are connected to each other.
21. The light emitting device of claim 20 , further comprising an extension part extending from a pad electrically connected to the first conductivity type semiconductor layer.
22. The light emitting device of claim 1 , further comprising a film including the first and second wavelength converters.
23. The light emitting device of claim 1 , further comprising a film including a plurality of laminated layers,
wherein the first and second wavelength converters are disposed on different laminated layers.
24. A light emitting device comprising:
a substrate;
a first light emitting cell, a second light emitting cell, and a third light emitting cell respectively disposed on the substrate and configured to respectively emit red light, green light, and blue light through an upper surface thereof;
pads electrically connected to the first, second, and third light emitting cells;
partition walls disposed between of the first light emitting cell, the second light emitting cell, and the third light emitting cell, respectively, and configured to not transmit light, the partition walls having upper surfaces facing the same direction as the upper surfaces of the first, second, and third light emitting cells; and
a protective layer covering the first, second, and third light emitting cells and disposed on the upper surfaces of the partition walls, and filling at least a portion of an area defined between adjacent partition walls,
wherein:
each of the first, second, and third light emitting cells has an upper surface facing away from the substrate and through which light exists the corresponding light emitting cell, and a lower surface opposite to the upper surface;
the pads are disposed on the lower surfaces of the first, second, and third light emitting cells;
a height of each of the first, second, and third light emitting cells is lower than a height of each partition wall; and
a distance between the partition walls and the first, second, and third light emitting cells is less than about 5 μm.
25. A display apparatus comprising:
a circuit board; and
a plurality of pixels arranged on the circuit board,
wherein each of the plurality of pixels includes the light emitting device of claim 24 .