LEDs with three color RGB pixels for displays
Devices and methods of forming the devices are disclosed. The device includes a substrate and a color LED pixel disposed on the substrate. The color LED pixel includes a red LED, a green LED and a blue LED. Each of the color LED includes a specific color LED body disposed on the respective color region on the substrate, a specific color multiple quantum well (MQW) on the respective color LED body and a specific color top LED layer disposed over the respective color MQW. The MQWs of the red LED, green LED and blue LED includes at least an indium gallium nitride (In x Ga 1-x N) layer and a gallium nitride (GaN), where x is the atomic percentage of In in the In x Ga 1-x N layer, and the MQWs of the red LED, green LED and blue LED have different bandgaps by varying x of the In x Ga 1-x N layer in the red LED, the green LED and the blue LED.
1. A device comprising:
a substrate;
a light emitting diode (LED) body disposed on the substrate, wherein the LED body comprises a fin body, the fin body being an elongated member disposed in a row direction;
a multiple quantum well (MQW) disposed on the LED body;
a top LED layer disposed on the MQW; and
wherein the LED body, the MQW and the top LED layer form an LED.
2. The device of claim 1 , wherein the LED comprises a red LED.
3. The device of claim 2 , wherein the MQW comprises at least an indium gallium nitride (In x Ga 1-x N) layer and a gallium nitride (GaN) layer, where x is an atomic percentage of In in the In x Ga 1-x N layer and is selected to produce a red bandgap.
4. The device of claim 3 , wherein x is about 35-40%.
5. The device of claim 1 , wherein the LED comprises a green LED.
6. The device of claim 5 , wherein the MQW comprises at least an In x Ga 1-x N layer and a GaN layer, where x is an atomic percentage of In in the In x Ga 1-x N layer and is selected to produce a green bandgap.
7. The device of claim 6 , wherein x is about 25-30%.
8. The device of claim 1 , wherein the LED comprises a blue LED.
9. The device of claim 8 , wherein the MQW comprises at least an In x Ga 1-x N layer and a GaN layer, where x is an atomic percentage of In in the In x Ga 1-x N layer and is selected to produce a blue bandgap.
10. The device of claim 9 , wherein x is about 15-20%.
11. A device comprising:
a substrate;
a light emitting diode (LED) body disposed on the substrate;
a multiple quantum well (MOW) disposed on the LED body;
a top LED layer disposed on the MQW; and
wherein
the LED body, the MOW and the top LED layer form an LED,
the substrate comprises a surface plane with a (111) crystal orientation, and
the LED body comprises an epitaxial layer, wherein sides of the LED body are along an m-plane and a top of the LED body is along a c-plane.
12. The device of claim 1 , wherein:
the LED body comprises a red LED body for a red LED disposed on a red region on the substrate, a green LED body for a green LED disposed on a green region on the substrate and a blue LED body for a blue LED disposed on a blue region on the substrate;
the MQW comprises a red MQW disposed on the red LED body, a green MQW disposed on the green LED body and a blue MQW disposed on the blue LED body;
the top LED layer comprises a red top layer disposed on the red MQW, a green top layer disposed on the green MQW and a blue top layer disposed on the blue MQW; and
the LED body, the MQW and the top LED layer form a colored LED pixel.
13. The device of claim 12 , wherein:
the red MQW comprises at least a red In x Ga 1-x N layer and a red GaN layer, where x is an atomic percentage of In in the red In x Ga 1-x N layer and is selected to produce a red bandgap;
the green MQW comprises at least a green IN x Ga 1-x N layer and a GaN layer, where x is the atomic percentage of In in the green In x Ga 1-x N layer and is selected to produce a green bandgap; and
the blue MQW comprises at least a blue In x Ga 1-x N layer and a blue GaN layer, where x is the atomic percentage of In in the blue In x Ga 1-x N layer and is selected to produce a blue bandgap.
14. The device of claim 13 , wherein:
x for the blue In x Ga 1-x N layer is about 15-20%;
x for the green In x Ga 1-x N layer is about 25-30%; and
x for the red In x Ga 1-x N layer is about 35-40%.
15. The device of claim 12 , wherein:
the colored LED pixel comprises a fin-type LED pixel having the fin body which serves as a common fin body for the red LED, the green LED and the blue LED;
the fin body includes
the red region which serves as the red LED body,
the green region which serves as the green LED body, and
the blue region which serves as the blue LED body; and
the fin body with the red LED, the green LED and the blue LED forms an LED unit of the colored LED pixel.
16. A device comprising:
a substrate;
a light emitting diode (LED) body disposed on the substrate, wherein the LED body comprises a nanowire body;
a multiple quantum well (MQW) disposed on the LED body;
a top LED layer disposed on the MOW; and
wherein the LED body, the MQW and the top LED layer form an LED.
17. The device in claim 15 , wherein the colored LED pixel comprises:
a plurality of LED units in the row direction, wherein red LEDs of the LED units are aligned in a column direction, green LEDs of the LED units are aligned in the column direction and blue LEDs of the LED units are aligned in the column direction; and
transparent conductive oxide (TCO) layers are disposed over the LEDs and are separated by an interconnect dielectric layer, wherein a TCO layer serves to couple same color LEDs of the LED units in the column direction.
18. The device of claim 16 , wherein:
the LED body comprises a red LED body for a red LED disposed on a red region on the substrate, a green LED body for a green LED disposed on a green region on the substrate and a blue LED body for a blue LED disposed on a blue region on the substrate;
the MOW comprises a red MOW disposed on the red LED body, a green MOW disposed on the green LED body and a blue MOW disposed on the blue LED body;
the top LED layer comprises a red top layer disposed on the red MOW, a green top layer disposed on the green MOW and a blue top layer disposed on the blue MOW; and
wherein the red LED body comprises a red nanowire body for the red LED, the green LED body comprises a green nanowire body for the green LED, and the blue LED body comprises a blue nanowire body for the blue LED.
19. The device of claim 18 , wherein the red nanowire body, the green nanowire body and the blue nanowire body have different cross-sectional diameters to incorporate different percentages (atomic percentages) of In, wherein:
a cross-sectional diameter of the red nanowire body is less than about 100 nm;
a cross-sectional diameter of the green nanowire body is about 200 nm; and
a cross-sectional diameter of the blue nanowire body is greater than about 300 nm.
20. A method for forming a device comprising:
providing a substrate;
forming a light emitting diode (LED) body on the substrate, wherein the LED body comprises a fin body or a nanowire body;
forming a multiple quantum well (MQW) on the LED body; and
forming a top LED layer on the MQW, wherein the LED body, the MQW and the top LED layer form an LED.