Uniform color phosphor-coated light-emitting diode
Light-emitting devices, and related components, systems and methods are disclosed.
1. A light-emitting device, comprising:
a multi-layer stack of materials including a light-generating region, a layer of p-doped semiconductor material, and a layer of n-doped semiconductor material supported by the light-generating region, a surface of the layer of n-doped semiconductor material being configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the layer of n-doped semiconductor material, the surface of the layer of n-doped semiconductor material having a dielectric function that varies spatially according to a pattern;
a support that supports the multi-layer stack of materials;
a layer of reflective material that is capable of reflecting at least about 50% of light generated by the light-generating region that impinges on the layer of reflective material, the layer of reflective material being between the support and the multi-layer stack of materials such that a distance between the layer of p-doped semiconductor material and the layer of reflective material is less than a distance between the layer of n-doped semiconductor material and the layer of reflective material; and
a phosphor material disposed on the surface of the layer of n-doped semiconductor material,
wherein sidewalls of the light-emitting device are substantially devoid of the phosphor material.
2. The light-emitting device of claim 1 , wherein the light emitting device is packaged.
3. The light-emitting device of claim 1 , wherein the light-emitting device is in the form of a packaged die.
4. The light-emitting device of claim 1 , wherein the light-emitting device is in the form of a packaged device that is free of an encapsulant.
5. The light-emitting device of claim 1 , further comprising a layer comprising a material that is substantially transparent to light that emerges from the light-emitting device.
6. The light-emitting device of claim 5 , wherein at least some of the phosphor material is disposed within the layer that comprises the material that is substantially transparent to light that emerges from the light-emitting device.
7. The light-emitting device of claim 1 , wherein the reflective material is a heat sink material.
8. The light-emitting device of claim 7 , wherein the heat sink material is configured so that the heat sink material has a vertical heat gradient during use of the light-emitting device.
9. The light-emitting device of claim 1 , further comprising a heat sink material.
10. The light-emitting device of claim 9 , wherein the heat sink material is configured so that the heat sink material has a vertical heat gradient during use of the light-emitting device.
11. The light-emitting device of claim 1 , further including a current-spreading layer between the layer of n-doped semiconductor material and the light-generating region.
12. The light-emitting device of claim 1 , further comprising electrical contacts configured to inject current into the light-emitting device.
13. The light-emitting device of claim 12 , wherein the electrical contacts are configured to vertically inject electrical current into the light-emitting device.
14. The light-emitting device of claim 1 , wherein the light-emitting device is selected from the group consisting of light-emitting diodes, lasers, optical amplifiers, and combinations thereof.
15. The light-emitting device of claim 1 , wherein the light-emitting device comprises a light emitting diode.
16. The light-emitting device of claim 1 , wherein the light-emitting device is selected from the group consisting of OLEDs, flat surface-emitting LEDs, HBLEDs, and combinations thereof.
17. The light-emitting device of claim 1 , wherein the pattern has an ideal lattice constant and a detuning parameter with a value greater than zero.
18. The light-emitting device of claim 1 , wherein the pattern does not extend into the light-generating region.
19. The light-emitting device of claim 1 , wherein the pattern does not extend beyond the layer of n-doped semiconductor material.
20. The light-emitting device of claim 1 ,
wherein the light-generating region is between the layer of reflective material and the layer of n-doped semiconductor material.
21. The light-emitting device of claim 1 , wherein the phosphor material is in the form of a layer, and a thickness of the layer of the phosphor material varies by less than about 20%.
22. The light-emitting device of claim 1 , wherein the pattern is nonperiodic pattern or a complex periodic pattern.
23. The light-emitting device of claim 1 , wherein the surface of the layer of n-doped semiconductor material has features with a size of less than about λ/5, where λ is a wavelength of light that can be generated by the light-generating region and that can emerge from the light-emitting device via the surface of the layer of n-doped semiconductor material.