Disclosed herein is an infrared detector. The detector includes a plurality of pixels. Each pixel includes an n-type semiconductor top contact layer, a p-type semiconductor layer electrically connected to the n-type top contact layer to form a top p-n junction, a unipolar electron barrier electrically connected to the p-type semiconductor layer, a bottom absorber, and an n-type semiconductor bottom contact layer electrically connected to the bottom absorber. The unipolar electron barrier is positioned between the p-type semiconductor layer and the bottom absorber.