Tunneling barrier infrared detector devices
Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.
1. An infrared detector device comprising:
a first contact layer;
an absorber layer adjacent to the first contact layer, wherein the absorber layer is doped p-type;
a hole barrier layer adjacent to the absorber layer, wherein:
a bandgap of the hole barrier layer is greater than a bandgap of the absorber layer; and
the hole barrier layer comprises a p-n junction;
a first barrier layer adjacent to the hole barrier layer, wherein a valence band offset of the first barrier layer is above a conduction band offset that is within the hole barrier layer at an interface between the hole barrier layer and the first barrier layer;
a second barrier layer adjacent to the first barrier layer; and
a second contact layer adjacent to the second barrier layer.
2. The infrared detector device of claim 1 , wherein the first barrier layer, the second barrier layer, and the second contact layer are doped p+.
3. The infrared detector device of claim 1 , wherein:
the first barrier layer comprises (GaSb) x (AlAs 0.08 Sb 0.92 ) 1-x that is p doped; and
the second barrier layer comprises (GaSb) y (AlAs 0.08 Sb 0.92 ) 1-y with y>x and a background p-type doping.
4. The infrared detector device of claim 3 , wherein the first barrier layer is p-doped to 3×10 18 cm −3 .
5. The infrared detector device of claim 3 , wherein the second barrier layer is p-doped on the order of 10 18 cm −3 .
6. The infrared detector device of claim 1 , wherein the second contact layer is n-doped.
7. The infrared detector device of claim 1 , wherein
the absorber layer comprises long-wave infrared material;
the hole barrier layer comprises mid-wave infrared material; and
the second contact layer comprises mid-wave infrared material.
8. The infrared detector device of claim 1 , wherein a tunneling structure is provided by the hole barrier layer and the first barrier layer.
9. The infrared detector device of claim 8 , wherein, during operation of the infrared detector device, minority electrons meet and recombine with majority holes on a barrier side of the tunneling structure.
10. A focal plane array comprising an array of infrared detector devices, each infrared detector device comprising:
a first contact layer;
an absorber layer adjacent to the first contact layer, wherein the absorber layer is doped p-type;
a hole barrier layer adjacent to the absorber layer, wherein:
a bandgap of the hole barrier layer is greater than a bandgap of the absorber layer; and
the hole barrier layer comprises a p-n junction;
a first barrier layer adjacent to the hole barrier layer, wherein a valence band offset of the first barrier layer is above a conduction band offset that is within the hole barrier layer at an interface between the hole barrier layer and the first barrier layer;
a second barrier layer adjacent to the first barrier layer; and
a second contact layer adjacent to the second barrier layer.
11. The focal plane array of claim 10 , wherein the first barrier layer, the second barrier layer, and the second contact layer are doped p+.
12. The focal plane array of claim 10 , wherein:
the first barrier layer comprises (GaSb) x (AlAs 0.08 Sb 0.92 ) 1-x that is p doped; and
the second barrier layer comprises (GaSb) y (AlAs 0.08 Sb 0.92 ) 1-y with y>x and a background p-type doping.
13. The focal plane array of claim 12 , wherein the first barrier layer is p-doped to 3×10 18 cm −3 .
14. The focal plane array of claim 12 , wherein the second barrier layer is p-doped on the order of 10 18 cm −3 .
15. The focal plane array of claim 10 , wherein the second contact layer is n-doped.
16. The focal plane array of claim 10 , wherein
the absorber layer comprises long-wave infrared material;
the hole barrier layer comprises mid-wave infrared material; and
the second contact layer comprises mid-wave infrared material.
17. The focal plane array of claim 10 , wherein a tunneling structure is provided by the hole barrier layer and the first barrier layer.
18. The focal plane array of claim 17 , wherein, during operation of the focal plane array, minority electrons meet and recombine with majority holes on a barrier side of the tunneling structure.