Light-emitting diode unit for display comprising plurality of pixels and display device having same
A light-emitting diode (LED) unit for a display including a plurality of pixels each including a first light emitting cell, a second light emitting cell, and a third light emitting cell, each of the first, second, and third light emitting cells including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, a first wavelength converter configured to convert a wavelength of light emitted from the first light emitting cell, a second wavelength converter configured to convert a wavelength of light emitted from the second light emitting cell, in which the first, second, and third light emitting cells of each pixel share the first conductivity type semiconductor layer.
1. A light-emitting diode (LED) unit for a display, comprising:
a plurality of pixels each including:
a first light emitting cell, a second light emitting cell, and a third light emitting cell, each of the first, second, and third light emitting cells including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer;
a first wavelength converter configured to convert a wavelength of light emitted from the first light emitting cell;
a second wavelength converter configured to convert a wavelength of light emitted from the second light emitting cell; and
pads electrically connected to the first, second, and third light emitting cells to independently drive the first, second, and third light emitting cells,
wherein the first, second, and third light emitting cells of each pixel overlap at least one of the pads.
2. The LED unit of claim 1 , wherein the first, second, and third light emitting cells are configured to be driven in a passive matrix or active matrix manner.
3. The LED unit of claim 1 , wherein:
the first, second, and third light emitting cells are configured to emit blue light;
the first wavelength converter is configured to convert blue light into red light; and
the second wavelength converter is configured to convert blue light into green light.
4. The LED unit of claim 1 , further comprising a third wavelength converter configured to convert a wavelength of light emitted from the third light emitting cell to a shorter wavelength than that converted by the first or second wavelength converter,
wherein the first, second, and third light emitting cells are configured to emit ultraviolet light.
5. The LED unit of claim 4 , wherein:
the first wavelength converter is configured to convert ultraviolet light into red light;
the second wavelength converter is configured to convert ultraviolet light into green light; and
the third wavelength converter is configured to convert ultraviolet light into blue light.
6. The LED unit of claim 1 , further comprising a light blocking layer disposed between the wavelength converters.
7. The LED unit of claim 1 , further comprising ohmic reflection layers disposed on the second conductivity type semiconductor layers of the first, second, and third light emitting cells, respectively.
8. The LED unit of claim 1 , further comprising a lower insulation layer disposed between the light emitting cells to prevent light interference between the light emitting cells.
9. The LED unit of claim 8 , wherein the lower insulation layer comprises a distributed Bragg reflector.
10. The LED unit of claim 1 , wherein the pads include:
the first, second, and third light emitting cells of each pixel share the first conductivity type semiconductor layer;
at least one common pad commonly electrically connected to the shared first conductivity type semiconductor layer; and
individual pads electrically connected to the second conductivity type semiconductor layers of the first, second, and third light emitting cells, respectively.
11. The LED unit of claim 10 , further comprising a support member covering side surfaces of the pads, the support member including a thermosetting or thermoplastic resin.
12. The LED unit of claim 1 , wherein at least two pixels share the same first conductivity type semiconductor layer.
13. The LED unit of claim 1 , wherein the pixels are arranged in a matrix form in the LED unit.
14. The LED unit of claim 1 , wherein four pixels are arranged in the LED unit.
15. A light-emitting diode (LED) unit for a display, comprising:
a plurality of pixels each including:
a first light emitting cell, a second light emitting cell, and a third light emitting cell, each of the first, second, and third light emitting cells including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer; and
a multi-layer laminated film including:
a first layer including a first wavelength converter configured to convert a wavelength of light emitted from the first light emitting cell; and
a second layer disposed on top of the first layer and including a second wavelength converter configured to convert a wavelength of light emitted from the second light emitting cell.
16. The LED unit of claim 15 , wherein the multi-layer laminated film further includes a third layer disposed on top of the second layer and including a third wavelength converter configured to convert a wavelength of light emitted from the third light emitting cell.
17. The LED unit of claim 16 , wherein the first, second, and third wavelength converters do not overlap each other.
18. The LED unit of claim 16 , wherein each of the first, second, and third layers comprises a transparent resin.
19. The LED unit of claim 16 , wherein the first, second, and third light emitting cells are configured to emit ultraviolet light.
20. The LED unit of claim 15 , further comprising pads electrically connected to the first, second, and third light emitting cells to independently drive the first, second, and third light emitting cells,
wherein the first, second, and third light emitting cells of each pixel overlap at least one of the pads.