Long-Wavelength Infrared Digital Focal Plane Arrays for Earth Remote Sensing Applications

In this presentation, we will report our recent efforts in achieving high performance in Antimonides type-II strained-layer superlattice (T2SLS) based infrared photodetectors using the barrier infrared detector (BIRD) device architecture. The recent emergence of barrier infrared detectors such as the nBn [1] and the XBn [2] have resulted in mid-wave infrared (MWIR) and long-wave infrared (LWIR) detectors with substantially higher operating temperatures than previously available in III-V semiconductor based MWIR and LWIR detectors. The initial nBn devices used either InAs absorber grown on InAs substrate, or lattice-matched InAsSb alloy grown on GaSb substrate, with cutoff wavelengths of ~3.2 µm and ~4 µm, respectively. While these detectors could operate at much higher temperatures than existing MWIR detectors based on InSb, their spectral responses do not cover the full (3 – 5.5 µm) MWIR atmospheric transmission window. There also have been nBn detectors based on the InAs/GaSb type-II superlattice absorber [3] .