Solid state lighting devices with improved contacts and associated methods of manufacturing
Solid state lighting (“SSL”) devices with improved contacts and associated methods of manufacturing are disclosed herein. In one embodiment, an SSL device includes an SSL structure having a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials. The SSL device also includes a first contact on the first semiconductor material and a second contact on the second semiconductor material, where the first and second contacts define the current flow path through the SSL structure. The first or second contact is configured to provide a current density profile in the SSL structure based on a target current density profile.
1. A solid state lighting (“SSL”) device, comprising:
a substrate;
an SSL structure on the substrate, the SSL structure having a first semiconductor material proximate the substrate, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials;
a first contact on the first semiconductor material;
a second contact on the second semiconductor material, wherein the first and second contacts define a current flow path through the SSL structure; and
wherein the second contact includes an insulative material and a transparent conductive material, and wherein
the insulative material has a surface facing away from the second semiconductor material and a plurality of openings at the surface, and wherein the insulative material has a first insulative portion and a second insulative portion positioned to straddle the first insulative portion, and wherein the first insulative portion has a first contact resistance, and wherein the second insulative portion has a second contact resistance, and wherein the first contact resistance is higher than the second contact resistance, and
the conductive material has a first portion in the openings and a second portion extending laterally on the surface of the insulative material, wherein at least a portion of light generated by the active region exits the SSL device through the conductive material, and
wherein the second contact is configured to provide defined current flow paths through the first and second semiconductor materials that provide a current density profile in the SSL structure based on a target current density profile.
2. The SSL device of claim 1 wherein the insulative material is configured to impede a current flow through a region of the SSL structure.
3. The SSL device of claim 1 wherein the conductive material is configured to increase a current conductance through a region of the SSL structure.
4. The SSL device of claim 1 wherein at least one of the openings has a shape that is different from the other openings.
5. The SSL device of claim 1 wherein at least one of the openings has a size that is different from the other openings.
6. The SSL device of claim 1 wherein at least one of the openings has a shape and size that are different from the other openings.
7. The SSL device of claim 1 wherein the plurality of openings extend from the second semiconductor material to the surface of the insulative material.
8. The SSL device of claim 1 wherein the conductive material is selected from the group consisting of indium tin oxide, aluminum zinc oxide, and fluorine-doped tin oxide.
9. The SSL device of claim 1 wherein
the first portion is selected from the group consisting of copper, aluminum, silver, gold, and platinum; and
the second portion is selected from the group consisting of indium tin oxide, aluminum zinc oxide, and fluorine-doped tin oxide.
10. The SSL device of claim 1 wherein the substrate includes silicon.
11. The SSL device of claim 1 wherein the second portion of the second contact is a contact portion.
12. An SSL device, comprising:
an SSL structure having a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials;
a first contact on the first semiconductor material;
a second contact on the second semiconductor material; and
wherein the first or the second contact includes an insulative material and a transparent conductive material, and wherein
the insulative material has a surface facing away from the corresponding first or second semiconductor material and a plurality of openings at the surface, and wherein the insulative material has a first insulative portion and a second insulative portion positioned to straddle the first insulative portion, and wherein the first insulative portion has a first contact resistance, and wherein the second insulative portion has a second contact resistance, and wherein the first contact resistance is higher than the second contact resistance, and
the conductive material has a first portion in the openings and a second portion extending laterally on the surface of the insulative material, wherein at least a portion of light generated by the active region exits the SSL device through the conductive material.
13. An SSL device, comprising:
a substrate material including silicon;
a first semiconductor material on the substrate material;
a second semiconductor material;
an active region between the first and second semiconductor materials;
a first contact on the first semiconductor material;
a second contact on the second semiconductor material, wherein the second contact includes an insulative material and a transparent conductive material, and wherein
the insulative material has a surface facing away from the second semiconductor material and a plurality of openings at the surface, wherein at least one of the openings has a shape and size that is different from the other openings, and wherein the insulative material has a first insulative portion and a second insulative portion positioned to straddle the first insulative portion, and wherein the first insulative portion has a first contact resistance, and wherein the second insulative portion has a second contact resistance, and wherein the first contact resistance is higher than the second contact resistance, and
the conductive material has a first portion in the openings and a second portion extending laterally on the surface of the insulative material, wherein at least a portion of light generated by the active region exits the SSL device through the conductive material.
14. The SSL device of claim 13 wherein the conductive material is selected from the group consisting of indium tin oxide, aluminum zinc oxide, and fluorine-doped tin oxide.