InAs/GaAsSb Type-II Superlattice LWIR Focal Plane Arrays Detectors Grown on InAs Substrates

InAs/GaAsSb type-II superlattice (T2SL) materials grown at a higher temperature and lattice-matched to InAs substrates are considered to have significant advantages in long wavelength infrared (LWIR) detection. In this work, an InAs/GaAsSb T2SL LWIR focal plane array (FPA) was fabricated and evaluated. The FPA has a format of 320 x 256 with a pixel pitch of 30 mu m and exhibits a 100% cutoff wavelength of 9.5 mu m at 80 K. Under a bias of -0.02V, the detectors show a dark current of 1.7 x 10(-5) A/cm(2) and a differential resistance-area of 1.5 x 10(3) Omega . cm(2). The noise equivalent temperature difference and operability of the FPA are 20.7 mK and 99.2% respectively under an integration time of 400 mu s, a 300 K background and F/2.0 optics. This high-performance FPA further verifies the feasibility of InAs/GaAsSb T2SL in LWIR detection.