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;
an n++ layer adjacent the hole barrier layer, wherein a thickness of the n++ layer is less than a thickness of the hole barrier layer;
a barrier layer adjacent to the n++ layer, wherein the barrier layer is doped p++ and a valance band offset within the barrier layer is higher than a conduction band offset within the n++ layer; and
a second contact layer adjacent to the barrier layer, wherein the second contact layer is doped p+.
2. The infrared detector device of claim 1 , wherein the absorber layer comprises long-wave infrared material.
3. The infrared detector device of claim 2 , wherein the hole barrier layer comprises mid-wave infrared material.
4. The infrared detector device of claim 3 , wherein the second contact layer comprises mid-wave infrared material.
5. The infrared detector device of claim 1 , wherein a bandgap of the n++ layer is the same as a bandgap of the hole barrier layer.
6. The infrared detector device of claim 1 , wherein, during operation of the infrared detector device, carriers propagate through the infrared detector device by band-to-band tunneling.
7. The infrared detector device of claim 1 , wherein the barrier layer comprises AlAs 0.08 Sb 0.92 .
8. 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;
an n++ layer adjacent the hole barrier layer, wherein a thickness of the n++ layer is less than a thickness of the hole barrier layer;
a barrier layer adjacent to the n++ layer, wherein the barrier layer is doped p++ and a valance band offset within the barrier layer is higher than a conduction band offset within the n++ layer; and
a second contact layer adjacent to the barrier layer, wherein the second contact layer is doped p+.
9. The focal plane array of claim 8 , wherein the absorber layer comprises long-wave infrared material.
10. The focal plane array of claim 9 , wherein the hole barrier layer comprises mid-wave infrared material.
11. The focal plane array of claim 10 , wherein the second contact layer comprises mid-wave infrared material.
12. The focal plane array of claim 8 , wherein a bandgap of the n++ layer is the same as a bandgap of the hole barrier layer.
13. The focal plane array of claim 8 , wherein, during operation of the infrared detector device, carriers propagate through the infrared detector device by band-to-band tunneling.
14. The focal plane array of claim 8 , wherein the barrier layer comprises AlAs 0.08 Sb 0.92 .