High operating temperature split-off band infrared detectors
View Patent ↗Systems and methods for at or near room temperature of infrared detection are disclosed. Embodiments of the disclosure include high temperature split-off band infrared detectors. One embodiment, among others, comprises a first barrier and a second barrier with an emitter disposed between the first and second barrier, each barrier being a layer of a first semiconductor material and the emitter being a layer of a second semiconductor material.
1. A photodetector comprising:
a first barrier and a second barrier, each barrier being a layer of a first semiconductor material; and
an emitter disposed between the first and second barriers so as to form a heterojunction at each interface between the emitter and the first and second barriers, the emitter being a layer of a second semiconductor material different from the first semiconductor material and having a split-off response to optical signals and further having a cutoff wavelength.
2. The photodetector of claim 1 , wherein the split-off response occurs over a range of wavelengths, the range having an upper limit.
3. The photodetector of claim 2 , wherein the cutoff wavelength is within one times the upper limit.
4. The photodetector of claim 2 , wherein the cutoff wavelength is within two times the upper limit.
5. The photodetector of claim 2 , wherein the cutoff wavelength is within four times the upper limit.
6. The photodetector of claim 1 , wherein the first semiconductor material comprises a first group III element, a second group III element, and a first group V element.
7. The photodetector of claim 6 , wherein the first group III element is selected from: Al, Ga, In, and combinations thereof,
the second group III element is selected from: Al, Ga, In, and combinations thereof, and
the first group V element is selected from: N, P, As, Sb, and combinations thereof.
8. The photodetector of claim 6 , wherein the first group III element is Al, the second group III element is Ga, and the first group V element is As.
9. The photodetector of claim 1 , wherein the first semiconductor material comprises Al 0.57 Ga 0.43 As.
10. The photodetector of claim 1 , wherein the second semiconductor material comprises a third group III and a second group V element.
11. The photodetector of claim 10 , wherein the third group III element is selected: Al, Ga, In, and combinations thereof, and
the second group V element is selected from: N, P, As, Sb, and combinations thereof.
12. The photodetector of claim 10 , wherein the emitter is doped with at least one doping element selected from: group II elements, group IV elements, and combinations thereof.
13. The photodetector of claim 12 , wherein the group II element is selected from: Be, Mg, and combinations thereof, and the group IV element is C.
14. The photodetector of claim 1 , wherein the emitter comprises GaAs.
15. The photodetector of claim 14 , wherein the split-off response occurs over a range of wavelengths, the range having an upper limit of about 3.6 μm.
16. The photodetector of claim 15 , wherein the cutoff wavelength is in the range of about 4 μm to 8 μm.
17. The photodetector of claim 1 , wherein an operating temperature exceeds room temperature.
18. A photodetector comprising:
a plurality of barriers, each of the plurality of barriers being a layer of a first semiconductor material; and
a plurality of emitters, each of the plurality of emitters being a layer of a second semiconductor material different from the first semiconductor material and having a split-off response to optical signals and further having a cutoff wavelength; wherein
each of the plurality of barriers is disposed adjacent to at least one of the plurality of emitters so as to form a heterojunction at each interface between each of the plurality of barriers and at least one of the plurality of emitters.
19. The photodetector of claim 18 , wherein the plurality of barriers comprise at least thirty-one layers, and the plurality of emitters comprise at least thirty emitters.
20. The photodetector of claim 18 , wherein the first semiconductor material comprises a first group III element, a second group III element, and a first group V element.
21. The photodetector of claim 20 , wherein the first semiconductor material comprises an amount of group III elements, and wherein the ratio, X, of the first group III element is in the range of about 0.05 to 0.70 and the ratio of the second group III element is 1−X.
22. The photodetector of claim 18 , wherein the second semiconductor material comprises a first group III element and a second group III element.
23. The photodetector of claim 22 , wherein the second semiconductor material comprises a p-dopant.
24. The photodetector of claim 23 , the p-dopant has a concentration of about 3×10 18 cm −3 .
25. A method of making of a photodetector, comprising the steps of:
providing an emitter base layer, the emitter base layer being a layer of a first semiconductor material,
disposing a first barrier on the base layer, the first barrier being a layer of a second semiconductor material,
disposing an emitter on the first barrier to form a heterojunction at a first interface between the emitter and the first barrier, the emitter being a layer of the first semiconductor material, wherein the first semiconductor material is a semiconductor differing from the second semiconductor material and having a split-off response to optical signals and further having a cutoff wavelength, and
disposing a second barrier on the emitter to form a heterojunction at a second interface between the emitter and the second barrier, the second barrier being a layer of the second semiconductor material.