Tunnel-junction structure incorporating N-type layer comprising nitrogen and a group VI dopant
View Patent ↗A tunnel junction structure comprises an n-type tunnel junction layer of a first semiconductor material, a p-type tunnel junction layer of a second semiconductor material and a tunnel junction between the tunnel junction layers. The first semiconductor material includes gallium (Ga), nitrogen (N), arsenic (As) and is doped with a Group VI dopant. The probability of tunneling is significantly increased, and the voltage drop across the tunnel junction is consequently decreased, by forming the tunnel junction structure of materials having a reduced difference between the valence band energy of the material of the p-type tunnel junction layer and the conduction band energy of the n-type tunnel junction layer. Doping the first semiconductor material n-type with a Group VI dopant maximizes the doping concentration in the first semiconductor material, thus further improving the probability of tunneling.
1. A light-emitting device, comprising:
an active region configured to generate light in response to injected charge; and
a tunnel junction structure located to inject charge into the active region and including an n-type tunnel junction layer of a first semiconductor material, a p-type tunnel junction layer of a second semiconductor material and a tunnel junction between the tunnel junction layers, the first semiconductor material including gallium (Ga), nitrogen (N), arsenic (As) and a Group VI dopant.
2. The light-emitting device of claim 1 , in which the n-type tunnel junction layer is located between the p-type tunnel junction layer and the active region.
3. The light-emitting device of claim 1 , in which the p-type tunnel junction layer is disposed between the n-type tunnel junction layer and the active region.
4. The light-emitting device of claim 1 , in which the Group VI dopant is chosen from sulfur (S), selenium (Se) and tellurium (Te).
5. The light-emitting device of claim 4 , in which the first semiconductor material consists essentially of gallium indium nitride arsenide Ga 1-x In x NAs in which x≧0.
6. The light-emitting device of claim 1 , in which the second semiconductor material includes gallium, nitrogen, arsenic and antimony.
7. The light-emitting device of claim 5 , in which:
an electromagnetic field intensity distribution exists in the light-emitting device; and
the tunnel junction is located at a minimum in the electromagnetic field intensity distribution.
8. The light-emitting device of claim 1 , in which:
the first semiconductor material consists essentially of gallium indium nitride arsenide GaInNAs; and
the second semiconductor material consists essentially of gallium nitride arsenide antimonide GaNAsSb.
9. The light-emitting device of claim 8 , in which:
the first semiconductor material consists essentially of gallium indium nitride arsenide Ga 1-w In w N x As 1-x , in which w≦0.4 and x≦0.15; and
the second semiconductor material consists essentially of gallium nitride arsenide antimonide GaN y As 1-y-z Sb z in which y≦0.15 and z≦0.3.
10. The light-emitting device of claim 1 , structured to generate light having a wavelength between 620 nm and 1650 nm.
11. The light-emitting device of claim 1 , in which the second semiconductor material comprises at least one of indium, antimony and bismuth.
12. A method of making a tunnel junction structure, the method comprising:
providing a substrate;
forming over the substrate an n-type tunnel junction layer of a first semiconductor material, the first semiconductor material including gallium (Ga), nitrogen (N), arsenic (As) and a Group VI dopant; and
forming over the substrate a p-type tunnel junction layer of a second semiconductor material juxtaposed with the n-type tunnel junction layer to form the tunnel junction.
13. The method of claim 12 , in which:
the second semiconductor material comprises gallium and two or more of nitrogen, arsenic, antimony and bismuth; and
the method additionally comprises doping the second semiconductor material p-type.
14. The method of claim 12 , further comprising:
doping the first semiconductor material n-type using a Group VI dopant chosen from sulfur (S), selenium (Se) and tellurium (Te).
15. A method for generating light, the method comprising:
forming an optical cavity;
locating an active region in the optical cavity, the active region configured to generate light in response to injected current;
forming a tunnel junction structure located to inject charge into the active region, including:
forming an n-type tunnel junction layer of a first semiconductor material including gallium (Ga), nitrogen (N), arsenic (As) and a Group VI dopant and
forming a p-type tunnel junction layer of a second semiconductor material juxtaposed with the n-type tunnel junction layer to create a tunnel junction; and
injecting current into the active region using the tunnel-junction structure.
16. The method of claim 15 , in which the active region is configured to generate light having a wavelength between 620 nm and 1650 nm.
17. The method of claim 15 , in which the Group VI dopant is chosen from sulfur (S), selenium (Se) and tellurium (Te).
18. A tunnel junction structure, comprising:
an n-type tunnel junction layer of a first semiconductor material including gallium (Ga), nitrogen (N), arsenic (As) and a Group VI dopant;
a p-type tunnel junction layer of a second semiconductor material; and
a tunnel junction between the tunnel junction layers.
19. The tunnel junction structure of claim 18 , in which the Group VI dopant is chosen from sulfur (S), selenium (Se) and tellurium (Te).
20. The tunnel junction structure of claim 18 , in which the first semiconductor material consists essentially of gallium indium nitride arsenide Ga 1-x In x NAs in which x≧0.
21. The tunnel junction structure of claim 18 , in which the second semiconductor material comprises gallium and two or more of nitrogen, arsenic, antimony and bismuth.
22. The tunnel junction structure of claim 18 , in which:
the first semiconductor material consists essentially of gallium indium nitride arsenide (GaInNAs); and
the second semiconductor material consists essentially of gallium nitride arsenide antimonide (GaNAsSb).
23. The tunnel junction structure of claim 22 , in which:
the first semiconductor material consists essentially of gallium indium nitride arsenide Ga 1-w In w N x AS 1-x , in which w≦0.4 and x≦0.15; and
the second semiconductor material consists essentially of gallium nitride arsenide antimonide GaN y As 1-y-z Sb z in which y≦0.15 and z≦0.3.