Title: Type-II Superlattice (T2SL) Barrier Infrared Detector (BIRD) for Earth Science Applications
Presenting Author: David Z. Ting
Organization: Jet Propulsion Laboratory, California Institute of Technology
Co-Author(s): Alexander Soibel, Arezou Khoshakhlagh, Sam A. Keo, Sir B. Rafol, Cory J. Hill, Anita Fisher, Edward M. Luong, Brian J. Pepper, Jason M. Mumolo, John K. Liu, Sarath D. Gunapala

Abstract:
Antimonide-based type-II superlattice (T2SL) is an artificially engineered III-V semiconductor material with a continuously adjustable cutoff wavelength ranging from ~2 to 14 micron and beyond. T2SL materials with distinct cutoff wavelengths can all be grown with high crystal quality on GaSb substrates (2, 3, and 4-inch-diameter formats are already available commercially; 5 and 6-inch have been demonstrated). Compared to HgCdTe (MCT), T2SL is more immune to tunneling, and can be tailored to suppress Auger generation; these dark-current-reducing properties are especially beneficial for long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) detectors. On the other hand, III-V-semiconductor-based T2SL are more susceptible to generation-recombination (G-R) and surface leakage dark currents than MCT. The barrier infrared detector (BIRD) uses the unipolar barrier device architecture, as exemplified by the nBn and the CBIRD (complementary barrier infrared detector) designs. The device architecture suppresses G-R and surface leakage dark currents (noise) without impeding the collection of photocurrent (signal). Mid-wavelength T2SL BIRD FPAs have demonstrated significantly higher operating temperature (HOT) than InSb FPAs with the same cutoff wavelength. LWIR detectors based on the BIRD architecture has also demonstrated significant operating temperature advantages over those based on traditional p-n junction designs. We will describe our effort in developing VLWIR detectors and focal plane arrays (FPAs) under the NASA Sustainable Land Imaging-Technology (SLI-T) program. In addition, we will also describe synergistic efforts in mid-wavelength infrared (MIWR) FPA development for the CubeSat Infrared Atmospheric Sounder (CIRAS), and LWIR FPA development for the Hyperspectral Thermal Emission Spectrometer (HyTES).