Efficient and directed nano-light emitting diode, and method for making same
The invention relates to light-emitting devices, and related components, systems and methods. In one aspect, the present invention is related to light emitting diode (LED) light extraction efficiency. A non-limiting example, the application teaches a method for improving light emitting diode (LED) extraction efficiency, by providing a nano-rod light emitting diode; providing quantum wells; and reducing the size of said nano-rod LED laterally in the quantum-well plane (x and y), thereby improving LED extraction efficiency.
1. A method for improving light emitting diode (LED) extraction efficiency, said method comprising:
(a) providing a nano-rod light emitting diode comprising a nano-rod;
(b) providing quantum wells having a quantum-well plane (x and y); and
(c) reducing diameter of the nano-rod of said nano-rod LED laterally in the quantum-well plane (x and y), thereby improving LED extraction efficiency.
2. The method of claim 1 , wherein the extraction efficiency achieved is from about 60% to about 100%.
3. The method of claim 1 , wherein the rod diameter of the nano-rod light emitting diode is reduced to about 200 nm and a number of guided modes is 3.
4. The method of claim 1 , wherein the radiation pattern of the LED becomes more directional when compared to a standard LED.
5. The method of claim 1 , wherein the quantum wells are placed inside the nano-rod.
6. The method of claim 1 , wherein all of the guided modes inside of said nano-rod light emitting diode are eliminated, except for HE 11 .
7. The method of claim 1 , wherein said method comprises eliminating the guided modes, except for the HE 11 mode, inside the nano-rod light emitting diode.
8. The method of claim 1 , wherein the rod-diameter is reduced to a sub-λ confinement regime.
9. The method of claim 1 , wherein the light emitting diode's radiation pattern is modified, such that the radiation pattern does not follow the Lambertian pattern of a normal LED, and its angular extend is narrower with a half-power point at θ=35° .
10. A nano-rod light emitting diode that has quantum wells inside of it and wherein rod-diameter of the nano-rod light emitting diode is about 200 nm and a number of guided modes is 3.
11. The nano-rod LED of claim 10 , wherein the radiation pattern of the LED is more directional when compared to a standard LED.
12. A method for making a nano-rod LED that is reduced in size laterally in a quantum-well plane (x and y), said method comprising:
(a) quantizing guided modes of the nano-rod LED;
(b) defining nano-rod pattern by E-beam lithography;
(c) depositing Nickel;
(d) performing inductively coupled plasma etching; and
(e) removing Nickel.