Light emitting diode and method of fabricating the same
View Patent ↗Disclosed herein is a light emitting diode, the structure of the light emitting diode comprises a substrate, a first-type semiconductor layer, a structural layer, a light emitting layer, a second-type semiconductor layer, a transparent conductive layer, a first contact pad and a second contact pad in regular turn. The structural layer comprises a stacked structure having a trapezoid sidewall and nano columns extending from the trapezoid sidewall in regular arrangement. Also, a method for fabricating the light emitting diode is disclosed.
1. A light emitting diode comprising:
a substrate having a surface with a cushion layer thereon with a first area and a second area;
a first-type semiconductor layer comprising a first portion and a second portion located in the first area and the second area, respectively;
a structural layer disposed on the second area of the cushion layer, comprising:
the second portion of the first-type semiconductor layer;
a light emitting layer disposed on the second portion of the first-type semiconductor layer; and
a second-type semiconductor layer disposed on the light emitting layer, wherein the structural layer is composed of a stacked structure having a trapezoid sidewall and nano columns, the trapezoid sidewall has an inclined surface, and a portion of the nano columns extends from the inclined surface in regular arrangement;
a transparent conductive layer disposed on the stacked structure of the structural layer in the second area of the cushion layer;
a first contact pad disposed on the first portion of the first-type semiconductor layer in the first area of the cushion layer; and
a second contact pad disposed on the transparent conductive layer.
2. The light emitting diode of claim 1 , wherein the ratio of the diameter of the nano columns and the thickness of the structural layer is in a range of 0.01 to 1.
3. The light emitting diode of claim 2 , wherein the space between the respective nano columns is in a range of 1 to 500 nm.
4. The light emitting diode of claim 1 , wherein the substrate is made of a sapphire substrate or a silicon substrate.
5. The light emitting diode of claim 1 , wherein the cushion layer is made of an undoped nitride semiconductor.
6. The light emitting diode of claim 1 , wherein the first-type semiconductor layer is an N-type semiconductor layer, and the second-type semiconductor layer is a P-type semiconductor layer.
7. The light emitting diode of claim 6 , wherein the N-type semiconductor layer is made of an N-type impurity-doped nitride semiconductor, and the P-type semiconductor layer is made of a P-type impurity-doped nitride semiconductor.
8. The light emitting diode of claim 7 , wherein the first-type semiconductor layer is an N-type gallium nitride layer, and the second-type semiconductor layer is a P-type gallium nitride layer.
9. The light emitting diode of claim 1 , wherein the light emitting layer is a multi-quantum well layer.
10. The light emitting diode of claim 9 , wherein the multi-quantum well layer comprises at least one gallium nitride layer and at least one indium gallium nitride layer.