Light emitting diode and method for manufacturing the same
View Patent ↗A light emitting diode includes a substrate, a first-type semiconductor layer, a nanorod layer and a transparent planar layer. The first-type semiconductor layer is disposed over the substrate. The nanorod layer is formed on the first-type semiconductor layer. The nanorod layer includes a plurality of nanorods and each of the nanorods has a quantum well structure and a second-type semiconductor layer. The quantum well structure is in contact with the first-type semiconductor layer, and the second-type semiconductor layer is formed on the quantum well structure. The transparent planar layer is filled between the nanorods. A surface of the second-type semiconductor layer is exposed out of the transparent planar layer.
1. A light emitting diode, comprising:
a substrate;
a first-type semiconductor layer disposed over the substrate;
a nanorod layer formed on the first-type semiconductor layer, the nanorod layer including a plurality of nanorods and each of the nanorods including a quantum well structure and a second-type semiconductor layer, wherein the quantum well structure is in contact with the first-type semiconductor layer, and the second-type semiconductor layer is formed on the quantum well structure; and
a transparent planar layer filled between the nanorods, wherein a surface of the second-type semiconductor layer is exposed out of the transparent planar layer;
wherein the first-type semiconductor layer, the nanorod layer and the transparent planar layer constitute a trapezoid sidewall structure.
2. The light emitting diode according to claim 1 , wherein the transparent planar layer is made of an insulating material comprising benzocyclobutene (BCB).
3. The light emitting diode according to claim 1 , wherein the quantum well structure has a width W and a height H, and the width W and the height H satisfy the following formula (I):
0.5 H≦W<10 H formula (I)
4. The light emitting diode according to claim 3 , wherein the width W is substantially equal to the height H.
5. The light emitting diode according to claim 4 , wherein the height H is about 5 nm to about 50 nm.
6. The light emitting diode according to claim 1 , wherein a spacing interval between any two adjacent nanorods is about 2 nm to about 3 nm.
7. The light emitting diode according to claim 1 , further comprising a transparent electrode layer that covers the transparent planar layer and a top portion of each of the second-type semiconductor layers.
8. The light emitting diode according to claim 7 , further comprising:
a first type contact pad disposed on the first-type semiconductor layer; and
a second type contact pad disposed on the transparent electrode layer.
9. The light emitting diode according to claim 1 , wherein the first-type semiconductor layer comprises a N-type gallium nitride layer, each of the quantum well structures comprises a multiple quantum well structure, and the second-type semiconductor layer comprises P-type gallium nitride.
10. The light emitting diode according to claim 1 , further comprising an undoped gallium nitride layer, and the undoped gallium nitride layer is disposed between the first-type semiconductor layer and the substrate.
11. The light emitting diode according to claim 1 , wherein the trapezoid sidewall structure has an oblique plane that forms an included angle of about 30 degrees to about 150 degrees with the substrate.