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; and
an active layer between the top doped layer and the bottom doped layer, the active layer comprising a quantum well layer between quantum barrier layers, wherein the quantum well layer is under biaxial tension.
2. The LED of claim 1 , wherein the quantum well layer comprises In x (Ga y Al 1−y ) 1−x P (x<0.5, y>0.9).
3. The LED of claim 2 , wherein the quantum well layer comprises Ga 0.6 In 0.4 P.
4. The LED of claim 2 , wherein the quantum barrier layers comprise AlInGaP.
5. The LED of claim 4 , wherein the quantum barrier layers comprise (Al 0.7 Ga 0.3 ) 0.5 In 0.5 P.
6. The LED of claim 2 , wherein a maximum lateral dimension between sidewalls of the p-n diode layer is 1 to 300 μm.
7. The LED of claim 1 ,
wherein the quantum barrier layers are doped with an n-type dopant spanning between lateral edges of the p-n diode layer.
8. The LED of claim 7 , wherein the n-type dopant is Si.
9. The LED of claim 7 , wherein the quantum barrier layers comprise a concentration of 1×10 17 cm −3 -1×10 18 cm −3 of the n-type dopant.
10. The LED of claim 7 , wherein the quantum barrier layers comprise AlInGaP.
11. The LED of claim 10 , wherein the quantum well layer comprises a material selected from the group consisting of GaInP and AlInGaP.
12. The LED of claim 7 , wherein a maximum lateral dimension between sidewalls of the p-n diode layer is 1 to 300 μm.
13. The LED of claim 7 , wherein the quantum well layer comprises In x (Ga y Al 1−y ) 1−x P (x<0.5, y>0.9), and the quantum barrier layers comprise AlInGaP.
14. The LED of claim 13 , wherein the quantum well layer comprises Ga 0.6 In 0.4 P.
15. The LED of claim 13 , wherein the n-type dopant is Si.
16. The LED of claim 1 , further comprising a diffused passivation layer within sidewalls of the p-n diode layer, wherein the diffused passivation layer comprises a diffused dopant selected from the group consisting of Mg and Zn, and the diffused passivation layer overlaps the active layer.
17. A light emitting diode (LED) comprising:
a mesa structure including:
a first bottom cladding layer;
a spacer layer over the first bottom cladding layer;
a second bottom cladding layer over the spacer layer;
an active layer over the second cladding layer; and
a top cladding layer over the active layer; and
a pillar structure below the first bottom cladding layer, wherein the pillar structure is in direct contact with the first bottom cladding layer, is centrally located at, and protrudes from the first bottom cladding layer.
18. The LED of claim 17 , wherein the first bottom cladding layer is thicker than the second bottom cladding layer, and the second bottom cladding layer comprises a higher Mg dopant concentration than the first bottom cladding layer.