Light emitting devices
Light-emitting devices, and related components, systems and methods are disclosed.
1. A light emitting device comprising:
a III-nitride semiconductor structure including an active region disposed between an n-type and a p-type region;
a photonic crystal structure formed in an n-type region; and
a reflector;
wherein the p-type region is substantially planar and the photonic crystal structure does not extend into the p-type region; and
wherein the reflector and the photonic crystal structure are disposed on opposite sides of the active region.
2. The device of claim 1 wherein the photonic crystal structure comprises a periodic variation in a thickness of the n-type region.
3. The device of claim 1 wherein the photonic crystal structure comprises a planar lattice of holes.
4. The device of claim 3 wherein the lattice has a lattice constant a between about 0.1λ and about 10λ, where λ is a wavelength of light emitted by the active region.
5. The device of claim 3 wherein the lattice has a lattice constant a and the holes have a diameter between about 0.1 a and about 0.5 a.
6. The device of claim 3 wherein the holes have a depth between about 0.05λ and about 5λ, where λ is a wavelength of light emitted by the active region.
7. The device of claim 3 wherein a lattice type, lattice constant, hole diameter, and hole depth are selected to create a predetermined radiation pattern.
8. The device of claim 3 wherein a lattice type, lattice constant, hole diameter, and hole depth are selected to create a radiation pattern having a maximum in power emitted in a direction substantially perpendicular to a surface of the semiconductor structure.
9. The device of claim 3 wherein a lattice type, lattice constant, hole diameter, and hole depth are selected such that at least 50% of total power emitted from the device is emitted in a 45° cone centered about an axis perpendicular to a surface of the device.
10. The device of claim 3 wherein a lattice type, lattice constant, hole diameter, and hole depth are selected such that at least 25% of total power emitted from the device is emitted in a 30° cone centered about an axis perpendicular to a surface of the device.
11. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a surface of an n-type region having a dielectric function that varies spatially according to a pattern, wherein the pattern does not extend beyond the n-type region; and
a reflector;
wherein the reflector and the surface of an n-type region having a dielectric function that varies spatially according to a pattern are disposed on opposite sides of the light-generating region.
12. The device of claim 11 , wherein the p-type region is substantially planar.
13. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a photonic lattice formed in an n-type region, wherein the photonic lattice does not extend beyond the n-type region; and
a reflector;
wherein the reflector and the photonic lattice are disposed on opposite sides of the light-generating region.
14. The device of claim 13 , wherein the p-type region is substantially planar.
15. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a surface of an n-type region having a dielectric function that varies spatially according to a pattern, wherein the pattern does not extend into the p-type region; and
a reflector;
wherein the reflector and the surface of an n-type region having a dielectric function that varies spatially according to a pattern are disposed on opposite sides of the light-generating region.
16. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a photonic lattice formed in an n-type region, wherein the photonic lattice does not extend into the p-type region; and
a reflector;
wherein the reflector and the photonic lattice are disposed on opposite sides of the light-generating region.
17. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a surface of an n-type region having a dielectric function that varies spatially according to a pattern, wherein the p-type region is substantially planar and the pattern does not extend into the p-type region; and
a reflector;
wherein the reflector and the surface of an n-type region having a dielectric function that varies spatially according to a pattern are disposed on opposite sides of the light-generating region.
18. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a photonic lattice formed in an n-type region, and
a reflector;
wherein the p-type region is substantially planar and the photonic lattice does not extend into the p-type region, and
wherein the reflector and the photonic lattice are disposed on opposite sides of the light-generating region.
19. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region; and
a surface of an n-type region having a dielectric function that varies spatially according to a pattern, wherein the pattern does not extend beyond the light-generating region
a reflector;
wherein the reflector and the surface of an n-type region having a dielectric function that varies spatially according to a pattern are disposed on opposite sides of the light-generating region.
20. The device of claim 19 , wherein the p-type region is substantially planar.
21. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a photonic lattice formed in an n-type region, wherein the photonic lattice does not extend beyond the light-generating region; and
a reflector;
wherein the reflector and the photonic lattice are disposed on opposite sides of the light-generating region.
22. The device of claim 21 , wherein the p-type region is substantially planar.
23. A light emitting device comprising:
a III-V semiconductor structure including a light-generating region disposed between an n-type region and a p-type region;
a photonic lattice formed in an n-type region, wherein the photonic lattice is formed of a pattern of holes extending from a surface of the n-type region; and
a reflector;
wherein the reflector and the photonic lattice are disposed on opposite sides of the light-generating region.
24. The device of claim 23 , wherein the holes do not extend beyond the n-type region.
25. The device of claim 23 , wherein the surface of the n-type region is substantially flat.