LED structures for reduced non-radiative sidewall recombination
LED structures are disclosed to reduce non-radiative sidewall recombination along sidewalls of vertical LEDs including p-n diode sidewalls that span a top current spreading layer, bottom current spreading layer, and active layer between the top current spreading layer and bottom current spreading layer.
1. A light emitting diode (LED) comprising:
a p-n diode layer including:
a top doped layer doped with a first dopant type;
a bottom doped layer doped with a second dopant type opposite the first dopant type;
an active layer between the top doped layer and the bottom doped layer; and
p-n diode layer sidewalls spanning the top doped layer, the active layer, and the bottom doped layer;
wherein lateral edges of the active layer are internally confined inside the p-n diode layer sidewalls.
2. The LED of claim 1 , further comprising an intermixed region surrounding the active layer and within the p-n diode layer sidewalls.
3. The LED of claim 2 , wherein the active layer includes a plurality of quantum well layers and a plurality of quantum barrier layers.
4. The LED of claim 3 , wherein the intermixed region comprises a higher bandgap than each of the plurality of quantum well layers.
5. The LED of claim 4 , wherein the intermixed region comprises a higher concentration of Al than each of the plurality of quantum well layers.
6. The LED of claim 4 , wherein the intermixed region comprises a lower concentration of In than each of the plurality of quantum well layers.
7. The LED of claim 4 , wherein the intermixed region comprises:
a higher concentration of Al than each of the plurality of quantum well layers; and
a lower concentration of In than each of the plurality of quantum well layers.
8. The LED of claim 4 , wherein the bottom doped layer is in-situ doped with a dopant of the second dopant type.
9. The LED of claim 8 , further comprising a profile of a second dopant of the second dopant type spanning the p-n diode layer sidewalls along the top doped layer, the active layer, and the bottom doped layer.
10. The LED of claim 9 , wherein the dopant of the second dopant type is Mg, and the second dopant of the second dopant type is Zn.
11. The LED of claim 9 , wherein the dopant of the second dopant type is Mg, and the second dopant of the second dopant type is Mg.
12. The LED of claim 4 , wherein each of the plurality of quantum well layers is thinner than each of the plurality of quantum barrier layers.
13. The LED of claim 12 , wherein each of the plurality of quantum well layers is 2-5 nm thick.
14. The LED of claim 4 , wherein each of the quantum barrier layers and each of the active layers comprises (Al x Ga (1−x)y In 1−y P, wherein Δx between the quantum barrier layers and the active layers is greater than 0.6, and the quantum barrier layers have a higher Al concentration than the active layers.
15. The LED of claim 4 , wherein each of the quantum barrier layers and each of the active layers comprises (Al x Ga (1−x)y In 1−y P, wherein Δx between the quantum barrier layers and the active layers is greater than 0.8, and the quantum barrier layers have a higher Al concentration than the active layers.
16. The LED of claim 15 , wherein x=1 for each of the quantum barrier layers.
17. The LED of claim 4 , wherein each of the quantum well layers is under compression.
18. The LED of claim 17 , wherein the intermixed region comprises a lower concentration of In than each of the plurality of quantum well layers.
19. The LED of claim 17 , wherein each of the quantum barrier layers is under tension.