LED with current injection confinement trench
A method and structure for forming an array of LED devices is disclosed. The LED devices in accordance with embodiments of the invention may include a confined current injection area, embedded mirror, or sidewall passivation layer, and any combination thereof.
1. An LED device comprising:
a p-n diode layer comprising:
a top surface with a maximum dimension of 3 to 20 μm,
a bottom surface comprising an interior bottom surface and a surrounding bottom surface;
external sidewalls extending between the top surface and the surrounding bottom surface;
a quantum well layer between an n-doped layer and a p-doped layer;
a confinement trench that extends from the bottom surface of the p-n diode layer through the quantum well layer and physically isolates an interior portion of the quantum well layer from a surrounding portion of the quantum well layer adjacent the external sidewalls, and the confinement trench physically isolates an interior bottom surface of the p-n diode layer from a surrounding bottom surface of the p-n diode layer adjacent the external sidewalls, wherein the surrounding bottom surface of the p-n diode completely surrounds the interior bottom surface of the p-n diode layer;
a bottom electrically conductive contact on and in electrical contact with the interior bottom surface of the p-n diode layer, wherein the bottom electrically conductive contact that is on and in electrical contact with the interior bottom surface of the p-n diode layer is not in electrical contact with the surrounding bottom surface of the p-n diode layer that completely surrounds the interior bottom surface of the p-n diode layer;
wherein the LED device is bonded to a bottom electrode of a subpixel within a display area of a display substrate, and the bottom electrically conductive contact is in electrical contact with the bottom electrode; and
a top electrode that is on and in electrical contact with the top surface, and the top electrode completely covers the top surface.
2. The LED device of claim 1 , further comprising a mirror layer spanning along the interior bottom surface and along confinement trench sidewalls within the confinement trench.
3. The LED device of claim 2 , wherein the mirror layer does not span along the external sidewalls of the p-n diode layer.
4. The LED device of claim 2 , further comprising a passivation layer between the mirror layer and the confinement trench sidewalls.
5. The LED device of claim 4 , wherein the passivation layer spans along the external sidewalls of the p-n diode layer.
6. The LED device of claim 4 , further comprising an opening in the passivation layer on the interior bottom surface of the p-n diode layer.
7. The LED device of claim 6 , wherein the mirror layer is formed within the opening of the passivation layer on the interior bottom surface of the p-n diode layer.
8. The LED device of claim 1 , wherein a top surface area of the top surface of the p-n diode layer is larger than a surface area of the interior bottom surface of the p-n-diode layer surrounded by the confinement trench.
9. The LED device of claim 1 , wherein the display substrate is incorporated within portable electronic device.