Nanowire sized opto-electronic structure and method for modifying selected portions of same
View Patent ↗A method for treating a LED structure with a substance, the LED structure includes an array of nanowires on a planar support. The method includes producing the substance at a source and causing it to move to the array along a line. The angle between the line followed by the substance and the plane of the support is less than 90° when measured from the center of the support. The substance is capable of rendering a portion of the nanowires nonconductive or less conductive compared to before being treated by the substance.
1. A LED structure comprising a support comprising a n-GaN buffer layer and an array of nanowires on the support, wherein the nanowires comprise a n-GaN core enclosed by a p-GaN shell, wherein the structure comprises:
(i) a n-electrode region comprising a first metal contact in direct contact with the n-GaN buffer layer; and
(ii) a p-electrode region comprising:
(a) a non-conductive layer that comprises the tips of the nanowires and a first portion of the sidewalls of a first group of the nanowires but not a second portion of the sidewalls of the first group of nanowires, wherein the non-conductive layer comprises a modified portion of the p-GaN shell that has been modified to reduce or eliminate its conductivity;
(b) a conductive layer in electrical contact with the second portion of the sidewalls of the first group of nanowires: and
(c) a second metal contact in direct contact with the conductive layer,
wherein the LED structure comprises at least one feature selected from:
a first feature wherein the modified portion of the p-GaN shell is modified by hydrogen to reduce or eliminate its conductivity;
a second feature wherein each of the first metal contact and the second metal contact comprises a respective instance of an identical set of metal contact layers and
a third feature wherein the conductive layer comprises transparent conductive oxide.
2. The LED structure of claim 1 , wherein the non-conductive layer comprises all the sidewalls of a second group of the nanowires, wherein the first group of nanowires are in the interior of the nanowire array and the second group of nanowires are on the exterior edge of the nanowire array.
3. The LED structure of claim 1 , wherein the LED structure comprises the first feature.
4. The LED structure of claim 1 , wherein the LED structure comprises the second feature.
5. The LED structure of claim 4 , wherein each instance of the identical set of metal contact layers comprises a layer of Al, a layer of Ti, and a layer of Au.
6. The LED structure of claim 4 , wherein each instance of the identical set of metal contact layers comprises an element selected from a layer of Ti and a layer of Au.
7. The LED structure of claim 4 , wherein each instance of the identical set of metal contact layers comprises a layer of Al.
8. The LED structure of claim 7 , wherein an instance of the Al layer is in direct contact with the n-GaN buffer layer in the n-electrode and another instance of the Al layer is in direct contact with the conductive layer in the p-electrode.
9. The LED structure of claim 4 , wherein each metal contact layer within the identical set of metal contact layers has a same thickness across the first metal contact and the second metal contact.
10. The LED structure of claim 4 , wherein:
the first metal contact is in direct contact with a surface of the n-GaN buffer layer that is located below a horizontal plane including an interface between the n-GaN buffer layer and the nanowires; and
the second metal contact is in direct contact with a surface of the conductive layer that is located above the horizontal plane including the interface between the n-GaN buffer layer and the nanowires.
11. The LED structure of claim 1 , wherein the LED structure comprises the third feature.
12. A LED structure comprising a support comprising a n-GaN buffer layer and an array of nanowires on the support, wherein the nanowires comprise a n-GaN core enclosed by a p-GaN shell, wherein the structure comprises
(i) a n-electrode region comprising a first metal contact in electrical contact with the n-GaN buffer layer; and
(ii) a p-electrode region comprising
(a) a non-conductive layer that comprises the tips of the nanowires and a first portion of the sidewalls of a first group of the nanowires but not a second portion of the sidewalls of the first group of nanowires, wherein the non-conductive layer comprises a modified portion of the p-GaN shell that has been modified to reduce or eliminate its conductivity;
(b) a transparent conductive oxide layer in electrical contact with the second portion of the sidewalls of the first group of nanowires; and
(c) a second metal contact in electrical contact with the transparent conductive oxide layer.
13. The LED structure of claim 12 , wherein each of the first metal contact and the second metal contact comprises a respective instance of an identical set of metal contact layers.
14. The LED structure of claim 12 , wherein the non-conductive layer comprises an insulating material layer on top of the tips and the portions of the sidewalls.
15. The LED structure of claim 12 , wherein the non-conductive layer comprises a modified portion of the p-GaN shell that has been modified to reduce or eliminate its conductivity.
16. The LED structure of claim 12 , wherein each metal contact layer within the identical set of metal contact layers has a same thickness across the first metal contact and the second metal contact.
17. The LED structure of claim 12 , wherein:
the first metal contact is in direct contact with a surface of the n-GaN buffer layer that is located below a horizontal plane including an interface between the n-GaN buffer layer and the nanowires; and
the second metal contact is in direct contact with a surface of the conductive layer that is located above the horizontal plane including the interface between the n-GaN buffer layer and the nanowires.
18. A LED structure comprising a support comprising a n-GaN buffer layer and an array of nanowires on the support, wherein the nanowires comprise a n-GaN core enclosed by a p-GaN shell, wherein the structure comprises
(i) a n-electrode region comprising a metal contact in electrical contact with the n-GaN buffer layer; and
(ii) a p-electrode region comprising
(a) a non-conductive layer that comprises the tips of the nanowires and a first portion of the sidewalls of a first group of the nanowires but not a second portion of the sidewalls of the first group of nanowires;
(b) a conductive layer in electrical contact with the second portion of the sidewalls of the first group of nanowires: and
(c) a metal contact in electrical contact with the conductive layer;
wherein the metal contacts comprise a layer of Al, a layer of Ti, and a layer of Au; and
wherein the Al layer is in direct contact with the n-GaN buffer layer in the n-electrode and the conductive layer in the p-electrode.
19. The LED structure of claim 18 , wherein the conductive layer comprises transparent conductive oxide.