Light-emitting diode chip and micro display device
A light-emitting diode (LED) chip and a display device having the same are provided. A green LED is regrown on a blue LED to produce blue and green light, and a red phosphor is disposed on the blue or green LED to produce red light. Red light, green light, and blue light are to be produced using a single LED chip. The single LED chip forms three subpixels therein so as to facilitate a transfer process of the LED chip to a display panel. The LED chip is configured based on the blue, green, and blue LEDs so as to facilitate the fabrication and driving of the LED chip.
1. A light-emitting diode chip, comprising:
a first semiconductor layer;
a first active layer disposed on the first semiconductor layer to emit light corresponding to a first wavelength band;
a second active layer disposed on the first semiconductor layer separately from the first active layer to emit light corresponding to a second wavelength band, the second active layer comprised of two regions;
a second semiconductor layer disposed on the first active layer and the two regions of the second active layer;
a phosphor layer disposed on one region of the two regions of the second active layer;
a first wall disposed between the first active layer and one region of the two regions of the second active layer; and
a second wall disposed between the two regions of the second active layer,
wherein the at least one wall of the first and second walls is disposed to separate at least a portion of the first semiconductor layer.
2. The light-emitting diode chip according to claim 1 , wherein the phosphor layer absorbs a portion of light corresponding to the second wavelength band, and emits light corresponding to a third wavelength band.
3. The light-emitting diode chip according to claim 1 , further comprising a color filter disposed on the phosphor layer to transmit light corresponding to a wavelength band other than the second wavelength band.
4. The light-emitting diode chip according to claim 3 , wherein highest points of the first and second walls are level with or higher than the color filter.
5. The light-emitting diode chip according to claim 1 , further comprising:
a first electrode connected to the first semiconductor layer; and
a plurality of second electrodes connected to the second semiconductor layer.
6. A micro display device, comprising:
a plurality of gate lines;
a plurality of data lines intersecting with the gate lines;
a plurality of pixels defined by the intersection between the gate lines and the data lines; and
a plurality of light-emitting diodes disposed in the pixels, respectively, each of the light-emitting diodes comprising:
a first semiconductor layer;
a first active layer disposed on the first semiconductor layer to emit light corresponding to a first wavelength band;
a second active layer disposed on the first semiconductor layer separately from the first active layer to emit light corresponding to a second wavelength band, the second active layer comprised of two regions;
a second semiconductor layer disposed on the first active layer and the two regions of the second active layer;
a phosphor layer disposed on one region of the two regions of the second active layer;
a first wall disposed between the first active layer and one region of the two regions of the second active layer; and
a second wall disposed between the two regions of the second active layer.
7. The micro display device according to claim 6 , wherein a portion of the first semiconductor layer, located below the first active layer, has a first height, and a portion of the first semiconductor layer, located below the first wall, has a second height, the first height being higher than the second height.
8. The micro display device according to claim 6 , wherein the phosphor layer absorbs a portion of light within the second wavelength band and emits light within a third wavelength band,
the micro display device further comprising a color filter disposed on the phosphor layer to transmit light corresponding to a wavelength band other than the second wavelength band.
9. The micro display device according to claim 6 , wherein each of regions, in which the first active layer and the two regions of the second active layer are disposed, forms a single subpixel.
10. The micro display device according to claim 9 , wherein the light-emitting diode further comprises:
a common electrode connected to the first semiconductor layer; and
two or more individual electrodes disposed in the subpixels, respectively, and connected to the second semiconductor layer.