InAs/InAsSb Type-II Superlattice Mid-Wavelength Infrared Focal Plane Array With Significantly Higher Operating Temperature Than InSb

Abstract

We report focal plane array (FPA) results on a mid-wavelength InAs/InAsSb type-II strained layer superlattice (T2SLS) unipolar barrier infrared detector with a cutoff wavelength of 5.4 μm. For 300 K background in the 3-5-μm band, f/2 aperture, an FPA operating at 150 K exhibits a mean noise equivalent differential temperature (NEDT) of 18.5 mK, and an NEDT operability of 99.7%. The NE T distribution has a width of 8 mK, with no noticeable distribution tail, indicating excellent uniformity. The mean noise-equivalent irradiance is 9.1 × 10 11 photons/sec-cm 2 . The mean quantum efficiency is 49.1% without antireflection coating, and the mean specific detectivity (D * ) is 2.53 × 10 11 cm-Hz ½ /W. Benefitting from an absorber material with a much longer Shockley-Read-Hall minority carrier lifetime, and a device architecture that suppresses generation-recombination and surface-leakage dark current, the InAs/InAsSb T2SLS barrier infrared detector FPA has demonstrated a significantly higher operating temperature than the mid-wavelength infrared market-leading InSb.

InAsSb-Based Infrared Photodetectors: Thirty Years Later On

“…In the last decade, the particular contribution in development of T2SLs InAs/InAsSb detectors and FPAs has given two research groups; group at Jet Propulsion Laboratory (JPL) [ 107 , 158 , 159 , 161 , 171 , 172 ] and the Razeghi group from Northwestern University [ 164 , 165 , 166 , 167 , 168 , 173 , 174 ]. Both groups have demonstrated the versatility of the T2SLs InAs/InAsSb with operating λ cut-off ranging from 2 to 14 μm and beyond.…”

“…Figure 75 shows the performance of the 24 μm pitch 640 × 512 FPA with λ cut-off ~5.4 μm (see Table 7 ) and direct injection (DI) ROIC with N w = 8 × 10 6 electrons. NEDT is below 19 mK for T < 160 K, and increases up to ~55 mK at 180 K. The operability is 99.7% up to 160 K and decreases to 99.3% at 180 K. NEDT exhibits excellent uniformity with 8 mK distribution [ 172 ]. Both NEDT and operability are similar to those described previously for 15 μm pitch nBn InAs 0.91 Sb 0.09 /B-AlAsSb 640 × 512 FPA shown in Figure 72 .…”

Infrared Digital Focal Plane Arrays for Earth Remote Sensing Instruments

“…Much has been discussed in the literature about the barrier infrared detector [1], and unipolar barriers in recent years. The ideal nBn structure would have two n-type region (n) separated by a larger bandgap, undoped barrier layer (B), where the n-B heterojunctions have a larger conduction band offsets and zero valence band offsets.…”

“…The recent emergence of BIRDs such as the nBn [1] and the XBn [1] have resulted in MWIR and 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 fixed cutoff wavelengths of ~3.2 μm and ~4 μm, respectively.…”

Influence of Pixel Etching on Electrical and Electro-Optical Performances of a Ga-Free InAs/InAsSb T2SL Barrier Photodetector for Mid-Wave Infrared Imaging

“…In the past ten years, barrier structure (called XBn) has become the standard design of antimonide-based (Sb-based) high-performance cooled infrared (IR) photodetectors, particularly for Ga-free InAsSb bulk and InAs/InAsSb type-II superlattice (T2SL) devices operating in the mid-wave infrared (MWIR, 3-5 µm) spectral domain [1][2][3][4][5][6][7][8][9][10][11].…”