Systems and methods for producing white-light light emitting diodes
A vertical light emitting diode (LED) includes a metal substrate; a p-electrode coupled to the metal substrate; a p-contact coupled to the p-electrode; a p-GaN portion coupled to the p electrode; an active region coupled to the p-GaN portion; an n-GaN portion coupled to the active region; and a phosphor layer coupled to the n-GaN.
1. A vertical light-emitting diode (LED) structure, comprising:
a metal substrate deposited adjacent to a p-electrode;
a p-GaN layer disposed above the p-electrode;
an active region for emitting light disposed above the p-GaN layer;
an n-GaN layer disposed above the active region; and
a wafer-level phosphor layer and an n-electrode disposed above the n-GaN layer, wherein the phosphor layer is parallel to the n-GaN layer.
2. The LED structure of claim 1 , wherein the metal substrate is deposited using at least one of electrochemical plating, electroless chemical plating, sputtering, chemical vapor deposition, e-beam evaporation, and thermal spray.
3. The LED structure of claim 1 , wherein the metal substrate comprises at least one of copper, nickel, aluminum, and alloys thereof.
4. The LED structure of claim 1 , further comprising a p-contact interposed between the metal substrate and the p-GaN layer, wherein the p-contact comprises a light reflector.
5. The LED structure of claim 1 , wherein the phosphor layer is spin-coated.
6. The LED structure of claim 5 , wherein the phosphor layer comprises a phosphor powder composition spin-coated on the n-GaN layer.
7. The LED structure of claim 6 , wherein the phosphor powder composition comprises phosphor particles mixed with one or more organic chemicals.
8. The LED structure of claim 1 , wherein the phosphor layer is patterned.
9. The LED structure of claim 1 , wherein the phosphor layer is dry-etched.
10. The LED structure of claim 1 , wherein the n-electrode is a metal bond pad coupled to the n-GaN layer through the phosphor layer.
11. The LED structure of claim 1 , wherein the phosphor layer contacts a surface of the n-GaN layer.
12. The LED structure of claim 11 , wherein the surface of the n-GaN layer is substantially smooth and planar.
13. The LED structure of claim 1 , wherein the thickness of the phosphor layer is substantially uniform.
14. A vertical light-emitting diode (LED) structure, comprising:
a metal substrate deposited adjacent to a p-electrode;
a p-GaN layer disposed above the p-electrode;
an active region for emitting light disposed above the p-GaN layer;
an n-GaN layer disposed above the active region;
a first wafer-level phosphor layer and an n-electrode disposed above the n-GaN layer, wherein the first phosphor layer is parallel to the n-GaN layer; and
a second phosphor layer coupled to the first phosphor layer.
15. The LED structure of claim 14 , wherein at least one of the first and the second phosphor layers is patterned.
16. The LED structure of claim 14 , wherein the surface of the n-GaN layer is substantially smooth and planar.
17. The LED structure of claim 14 , wherein the thickness of the first phosphor layer is substantially uniform.
18. The LED structure of claim 17 , wherein the thickness of the second phosphor layer is substantially uniform.
19. LED structure of claim 14 , wherein the metal substrate is deposited using at least one of electrochemical plating, electroless chemical plating, sputtering, chemical vapor deposition, e-beam evaporation, and thermal spray.
20. A vertical light-emitting diode (LED) structure, comprising:
a metal substrate deposited adjacent to a p-electrode;
a p-GaN layer disposed above the p-electrode;
an active region for emitting light disposed above the p-GaN layer;
an n-GaN layer disposed above the active region;
a first wafer-level phosphor layer and an n-electrode disposed above the n-GaN layer, wherein the first phosphor layer is parallel to the n-GaN layer; and
a second phosphor layer coupled to the first phosphor layer, wherein the first phosphor layer has a phosphor composition that is photosensitive to a different color than a phosphor composition of the second phosphor layer.