Enhanced quantum efficiency barrier infrared detectors

A detector array comprising:

• a two-dimensional array of detector structures comprising:
• a first contact layer formed from a p-type doped material, and a second contact layer formed from an n-type doped material, wherein at least the second contact layer does not include a hole blocking structure,
• a unipolar electron barrier having first and second sides, and wherein the first side is disposed adjacent the first contact layer, and
• a multi-segment absorber structure formed from at least a first absorber and a second absorber, wherein the first absorber is formed from a p-type absorber material and is disposed adjacent the second side of the unipolar electron barrier, and wherein the second absorber is formed from an n-type absorber material and is disposed between the first absorber and the second contact layer,
• wherein the second absorber is connected to the second contact layer either directly or by a transition region, wherein where a transition region is present the transition region is directly connected at a first side to the second contact layer and at a second side to the second absorber;
• and
• wherein the valence band edges of the unipolar electron barrier and multi-segment absorber structure are configured to minimize offset therebetween;
• and
• wherein the detector structures are mesa-isolated.