Type-II InAs/GaSb superlattice detectors based on CBIRD design

The closely lattice-matched material system of InAs, GaSb, and AlSb, commonly referred to as the 6.1 angstrom material system, enables many unique approaches for producing high performance infrared detectors. The flexibility of the materials system allows for superlattice structures that can be tailored to have cutoff wavelengths ranging from the short wave infrared to the very long wave infrared. The type-II superlattice design promises high optical properties due to normal incidence absorption, high uniformity, low tunneling currents, and suppressed Auger recombination. The antimonide material system also allows for the design of high performance barrier structures. In particular, unipolar barriers, which blocks one carrier type without impeding the flow of the other, have been implemented in the design of SL photodetectors to realize complex heterodiodes with improved performance. Here we report on growth and device performance of infrared photodetectors based on type II InAs/Ga(In)Sb strain layer superlattices (SLs) using the complementary barrier infrared detector (CBIRD) design.