Light emitting devices with high light collimation
Light-emitting devices, and related components, systems and methods are disclosed. The light-emitting device can include a multi-layer stack of materials and a support. The multi-layer stack of materials can include a light-generating region and a first layer supported by the light-generating. Thee light-generating region can be between the first layer and the support. The surface of the first layer can be configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the first layer. The surface of the first layer can have a dielectric function that varies spatially according to a pattern. The pattern can be formed of holes in the surface of the first layer. The pattern is configured so that light generated by the light-generating region that emerges from the light-emitting device via the surface of the first layer is more collimated than a Lambertian distribution of light.
1. A light-emitting device, comprising:
a multi-layer stack of materials including a light-generating region and a first layer supported by the light-generating region; and
a support;
wherein:
the light-generating region is between the first layer and the support;
a surface of the first layer is configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the first layer;
the surface of the first layer has a dielectric function that varies spatially according to a pattern;
the pattern is formed of holes in the surface of the first layer;
the pattern is configured so that light generated by the light-generating region that emerges from the light-emitting device via the surface of the first layer is more collimated than a Lambertian distribution of light; and
the pattern has an ideal lattice constant and a detuning parameter with a value greater than zero.
2. The light-emitting device of claim 1 , wherein, when light generated by the light-generating region emerges from the light-emitting device via the surface of the first layer, at least about 40% of the light emerging via the surface of the first layer emerges within at most about 30° of an angle normal to the surface of the first layer.
3. The light-emitting device of claim 1 , wherein the filling factor of the light-emitting device is at least about 10%.
4. The light-emitting device of claim 3 , wherein the filling factor of the light-emitting device is at most about 75%.
5. The light-emitting device of claim 1 , further comprising 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.
6. The light-emitting device of claim 5 , wherein the reflective material is a heat sink material.
7. The light-emitting device of claim 6 , 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.
8. The light-emitting device of claim 5 , further comprising a heat sink material.
9. The light-emitting device of claim 8 , 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.
10. The light-emitting device of claim 1 , further including a current-spreading layer between the first layer and the light-generating region.
11. The light-emitting device of claim 1 , further comprising electrical contacts configured to inject current into the light-emitting device.
12. The light-emitting device of claim 11 , wherein the electrical contacts are configured to vertically inject electrical current into the light-emitting device.
13. 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.
14. The light-emitting device of claim 1 , wherein the light-emitting device comprises a light emitting diode.
15. 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.
16. The light-emitting device of claim 1 , wherein the pattern does not extend into the light-generating region.
17. The light-emitting device of claim 1 , wherein the pattern does not extend and the first layer.
18. The light-emitting device of claim 1 , wherein the pattern extends beyond the first layer.
19. The light-emitting device of claim 1 , wherein the surface of the first layer 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 first layer.
20. A wafer, comprising:
a plurality of light-emitting devices, at least some of the light-emitting devices comprising:
a multi-layer stack of materials including a light-generating region and a first layer supported by the light-generating region; and
a support,
wherein:
the light-generating region is between the first layer and the support;
a surface of the first layer is configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the first layer;
the surface of the first layer has a dielectric function that varies spatially according to a quasi-crystalline pattern;
the quasi-crystalline pattern is formed of holes in the surface of the first layer;
the quasi-crystalline pattern is configured so that light generated by the light-generating region that emerges from the light-emitting device via the surface of the first layer is more collimated than a Lambertian distribution of light; and
the wafer includes at least about five light-emitting devices per square centimeter.
21. The wafer of claim 20 , wherein the wafer includes at least about 25 light-emitting devices per square centimeter.
22. The wafer of claim 20 , wherein the wafer includes at least about 50 light-emitting devices per square centimeter.
23. The wafer of claim 20 , wherein the surface of the first layer 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 first layer.
24. A light-emitting device, comprising:
a multi-layer stack of materials including a light-generating region and a first layer supported by the light-generating region; and
a support,
wherein:
the light-generating region is between the first layer and the supports;
a surface of the first layer is configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the first layer;
the surface of the first layer has a dielectric function that varies spatially according to a quasi-crystalline pattern;
the quasi-crystalline pattern is formed of holes in the surface of the first layer; and
the quasi-crystalline pattern is configured so that light generated by the light-generating region that emerges from the light-emitting device via the surface of the first layer is more collimated than a Lanibertian distribution of light.
25. The light-emitting device of claim 24 , wherein, when light generated by the light-generating region emerges from the light-emitting device via the surface of the first layer, at least about 40% of the light emerging via the surface of the first layer emerges within at most about 30° of an angle normal to the surface of the first layer.
26. The light-emitting device of claim 24 , wherein the filling factor of the light-emitting device is at least about 10%.
27. The light-emitting device of claim 26 , wherein the filling factor of the light-emitting device is at most about 75%.
28. The light-emitting device of claim 24 , further comprising 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.
29. The light-emitting device of claim 28 , wherein the reflective material is a heat sink material.
30. The light-emitting device of claim 29 , 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.
31. The light-emitting device of claim 28 , further comprising a heat sink material.
32. The light-emitting device of claim 31 , 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.
33. The light-emitting device of claim 24 , further including a current-spreading layer between the first layer and the light-generating region.
34. The light-emitting device of claim 24 , further comprising electrical contacts configured to inject current into the light-emitting device.
35. The light-emitting device of claim 34 , wherein the electrical contacts are configured to vertically inject electrical current into the light-emitting device.
36. The light-emitting device of claim 24 , wherein the light-emitting device is selected from the group consisting of light-emitting diodes, lasers, optical amplifiers, and combinations thereof.
37. The light-emitting device of claim 24 , wherein the light-emitting device comprises a light emitting diode.
38. The light-emitting device of claim 24 , wherein the light-emitting device is selected from the group consisting of OLEDs, flat surface-emitting LEDs, HBLEDs, and combinations thereof.
39. The light-emitting device of claim 24 , wherein the pattern does not extend into the light-generating region.
40. The light-emitting device of claim 24 , wherein the pattern does not extend beyond the first layer.
41. The light-emitting device of claim 24 , wherein the pattern extends beyond the first layer.
42. A wafer, comprising:
a plurality of light-emitting devices, at least some of the light-emitting devices comprising:
a multi-layer stack of materials including a light-generating region and a first layer supported by the light-generating region; and
a support,
wherein:
the light-generating region is between the first layer and the support;
a surface of the first layer is configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the first layer;
the surface of the first layer has a dielectric function that varies spatially according to a pattern;
the pattern is formed of holes in the surface of the first layer;
the pattern is configured so that light generated by the light-generating region that emerges from the light-emitting device via the surface of the first layer is more collimated than a Lambertian distribution of light;
for the at least some of the light-emitting devices, the pattern has an ideal lattice constant and a detuning parameter with a value greater than zero; and
the wafer includes at least about five light-emitting devices per square centimeter.
43. The wafer of claim 42 , wherein the wafer includes at least about 25 light-emitting devices per square centimeter.
44. The wafer of claim 42 , wherein the wafer includes at least about 50 light-emitting devices per square centimeter.
45. The light-emitting device of claim 42 , wherein the surface of the first layer 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 first layer.
46. The wafer of claim 42 , wherein, for all the light-emitting devices, the pattern has an ideal lattice constant and a detuning parameter with a value greater than zero.