Exclusion, extraction, and junction placement effects in the complementary barrier infrared detector

We demonstrate a long wavelength type-II superlattice (T2SL) complementary barrier infrared detector (CBIRD) with a double broken-gap junction bottom contact structure designed to reduce material growth demands without diminishing performance. Simulation suggests generation-recombination dark current suppression is the result of placing the electrical junction in the wide-gap hole barrier region, away from the metallurgical hole-barrier/ absorber heterojunction. The lower turn-on bias of the modified CBIRD is explained in terms of junction properties. We suggest that minority carrier exclusion and extraction effects are partially responsible for the observed low diffusion-limited CBIRD dark current despite short T2SL minority carrier lifetimes. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798551]