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We report a type-II InAs/GaSb superlattice three-color infrared detector for mid-wave (MW), long-wave (LW), and very long-wave (VLW) detections. The detector structure consists of three contacts of NIPIN architecture for MW and LW detections, and hetero-junction NIP architecture for VLW detection. It is found that the spectral crosstalks can be significantly reduced by controlling the minority carriers transport via doping beryllium in the two active regions of NIPIN section. The crosstalk detection at MW, LW, and VLW signals are achieved by selecting the bias voltages on the device. At 77K, the cutoff wavelengths of the three-color detection are 5.3 μm (at 0 mV), 14 μm (at 300 mV) and 19 μm (at −20 mV) with the detectivities of 4.6×1011 cm·Hz1/2 W−1, 2.3 × 1010 cm·Hz1/2W−1, and 1.0×1010 cm·Hz1/2W−1 for MW, LW and VLW. The crosstalks of the MW channel, LW channel, and VLW channel are almost 0, 0.25, and 0.6, respectively. [ABSTRACT FROM AUTHOR]

• Seawater immersion worsens the damage inflicted to brain tissue by open TBI. • Seawater upregulates oxidative stress in brain tissue. • Seawater increases neuron sensibility to apoptosis inducing factors. • Seawater promotes angiogenesis and astrogliosis in brain tissue. We emulated instances of open traumatic brain injuries (TBI) in a maritime disaster. New Zealand rabbit animal models were used to evaluate the pathophysiological changes in open TBI with and without the influence of artificial seawater. New Zealand rabbits were randomly divided into 3 groups. Control group consisted of only normal animals. Animals in TBI and TBI + Seawater groups underwent craniotomy with dura mater incised and brain tissue exposed to free-fall impact. Afterward, only TBI + Seawater group received on-site artificial seawater infusion. Brain water content (BWC) and permeability of blood–brain barrier (BBB) were assessed. Reactive oxygen species levels were measured. Western blotting and immunofluorescence were employed to detect: apoptosis-related factors Caspase-3, Bax and Bcl-2; angiogenesis-related factors CD31 and CD34; astrogliosis-related factor glial fibrillary acidic protein (GFAP); potential neuron injury indicator neuron-specific enolase (NSE). Hematoxylin & eosin, Masson-trichrome and Nissl stainings were performed for pathological observations. Comparing to Control group, TBI group manifested abnormal neuronal morphology; increased BWC; compromised BBB integrity; increased ROS, Bax, CD31, CD34, Caspase-3 and GFAP expressions; decreased Bcl-2 and NSE expression. Seawater immersion caused all changes, except BWC, to become more significant. Seawater immersion worsens the damage inflicted to brain tissue by open TBI. It aggravates hypoxia in brain tissue, upregulates ROS expression, increases neuron sensitivity to apoptosis-inducing factors, and promotes angiogenesis as well as astrogliosis. [ABSTRACT FROM AUTHOR]

A long-/long-wave dual-color detector with N-M-π-B-π-M-N structure was developed based on a type-II InAs/GaSb superlattice. The saturated responsivity was achieved under low bias voltage for both channels. The device could be operated as a single detector for sequential detection and showed high quantum efficiencies. The peak quantum efficiencies of long-wavelength infrared band-1 (blue channel) and long-wavelength infrared band-2 (red channel) were 44% at 6.3 μm under 20 mV and 57% at 9.1 μm under −60 mV, respectively. The optical performance for each channel was achieved using a 2 μm thickness absorber. Due to the high QE, the specific detectivities of the blue and red channels reached 5.0 × 1011 cm·Hz1/2/W at 6.8 μm and 3.1 × 1011 cm·Hz1/2/W at 9.1 μm, respectively, at 77 K. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate bias-selectable dual-band short- or mid-wavelength infrared photodetectors based on In0.24Ga0.76As0.21Sb0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2.2 μm and 3.6 μm, respectively. At 200 K, the short-wave channel exhibits a peak quantum efficiency of 42% and a dark current density of 5.93 × 10−5 A/cm2 at 500 mV, thereby providing a detectivity of 1.55 × 1011 cm⋅Hz1/2/W. The mid-wave channel exhibits a peak quantum efficiency of 31% and a dark current density of 1.22 × 10−3 A/cm2 at −300 mV, thereby resulting in a detectivity of 2.71 × 1010 cm⋅Hz1/2/W. Moreover, we discuss the band alignment and spectral cross-talk of the dual-band n-i-p-p-i-n structure. [ABSTRACT FROM AUTHOR]

In this paper we focused on the mask technology of inductively coupled plasma (ICP) etching for the mesa fabrication of infrared focal plane arrays (FPA). By using the SiO2 mask, the mesa has higher graphics transfer accuracy and creates less micro-ripples in sidewalls. Comparing the IV characterization of detectors by using two different masks, the detector using the SiO2 hard mask has the of , while the detector using the photoresist mask has the of in 77 K. After that we focused on the method of removing the remaining SiO2 after mesa etching. The dry ICP etching and chemical buffer oxide etcher (BOE) based on HF and NH4F are used in this part. Detectors using BOE only have closer to that using the combining method, but it leads to gaps on mesas because of the corrosion on AlSb layer by BOE. We finally choose the combining method and fabricated the 640× 512 FPA. The FPA with cutoff wavelength of 4.8 m has the average of and the average detectivity of at 77 K. The FPA has good uniformity with the bad dots rate of 1.21% and the noise equivalent temperature difference (NEDT) of 22.9 mK operating at 77 K. [ABSTRACT FROM AUTHOR]

A very long wavelength infrared(VLWIR) focal plane array based on InAs/GaSb type-II super-lattices is demonstrated on a GaSb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 m, at 77 K. A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of −20 mV, yielding a peak specific detectivity of cm·Hz ·W−1. The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK. [ABSTRACT FROM AUTHOR]