InAs/GaSb superlattice infrared detectors

Future heterojunction InAs/GaSb superlattice (SL) detector devices in the long-wavelength infrared regime (LWIR, 8–12 μm) require an accurate bandstructure model and a successful surface passivation. In this study, we have validated the superlattice empirical pseudopotential method developed by Dente and Tilton over a wide range of bandgap energies. Furthermore, dark current data for a novel dielectric surface passivation for LWIR devices is presented. Next, we present a technique for high-resolution, full-wafer mapping of etch pit densities on commercial (1 0 0) GaSb substrates, which allows to study the local correlation between threading dislocations in the substrate and the electro-optical pixel performance. Finally, recent performance data for 384 × 288 dual-color InAs/GaSb superlattice imagers for the mid-wavelength infrared (MWR, 3–5 μm) is given.

► InAs/GaSb superlattice heterojunction devices require precise bandstructure modeling.
► We experimentally validate the Superlattice (SL) Empirical Pseudopotential Method.
► Dark current data for LWIR InAs/GaSb SLs with a dielectric passivation is presented.
► The etch pit density of 3” (100) GaSb substrates is mapped at high spatial resolution.
► We show NETD data for a dual-color InAs/GaSb SL camera sensitive at 3-4 μm and 4-5μm.