Bolingbrook, IL, United States

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Grant
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: STTR | Phase: Phase II | Award Amount: 999.81K | Year: 2015

The primary goal of this proposed effort is to develop mid-wavelength infrared (MWIR) colloidal quantum dot (CQD)-based focal plane arrays (FPAs) to significantly reduce the cost of MWIR photon imagers. The current lack of such low-cost systems leaves unmet many civil and military needs, such as the broad deployment of tactical photon-detecting imagers, non-destructive testing cameras, and next generation night vision goggles. Phase I of this project showed that MWIR CQD FPAs are feasible: we synthesized CQDs with a low cost process in ambient air and demonstrated good MWIR response, and fabricated planar, single element devices that show room temperature photoresponse. These results are the foundation of modified synthesis techniques to improve the detectivity of current MWIR CQD thin films by at least one order of magnitude as well as FPA design studies and FPA fabrication during the proposed Phase II effort. The proposing company will partner with Prof. Guyot-Sionnests group at the University of Chicago. This synergistic effort will combine the CQD chemical synthesis expertise of the Guyot-Sionnest group and the infrared device capabilities of the Sivananthan Laboratories team.


Grant
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase I | Award Amount: 97.45K | Year: 2015

Absorber layers based on strained layer superlattice (SLS) composed of III-V compound semiconductors (e.g. GaSb and InAs/Sb) are a promising sensor technology for infrared imaging; however, dark currents and short carrier lifetimes in SLS are still significant problems. It is presently suspected that the short carrier lifetimes and some dark current arise due to a native point defect, possibly the Ga/In antisites (a III-group atom on the V-group sublattice), creating a mid-gap state within the SLS band gap that facilitates Shockley-Read-Hall generation/recombination. Sivananthan Laboratories, Inc. proposes to use molecular dynamics simulations to evaluate the types and distributions of defects as a function of MBE growth parameters, and tight binding electronic structure calculations to evaluate the effect of defects on lifetimes and hence dark currents, thus producing a fully computational method to relate MBE process parameters to device performance. Possible growth process improvements will be considered, based on the identified deleterious defects and associated process parameters, and tested using the proposed computational method. Experiments will then be performed to verify the theoretical understanding and optimize a growth process based on the theoretical predictions.


Grant
Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: STTR | Phase: Phase I | Award Amount: 100.00K | Year: 2014

The primary goal of this proposed effort is to develop mid-wavelength infrared (MWIR) colloidal quantum dot (CQD)-based focal plane arrays (FPAs) to significantly reduce the cost of MWIR photon imagers. In order to realize this goal, it will first be nec


Grant
Agency: Department of Defense | Branch: Office for Chemical and Biological Defense | Program: SBIR | Phase: Phase II | Award Amount: 1.05M | Year: 2014

The primary goal of this proposed work is to develop a long wavelength infrared (LWIR) colloidal quantum dot (CQD)-based focal plane array (FPA) and show its feasibility when used in a camera system and a hyperspectral imaging system. Phase I results cumulated in the first-ever synthesis of photoresponsive LWIR CQDs and CQD-based photodetectors at the single device level operating at room temperature. Furthermore, a CQD film compatible, commercially available read out integrated circuit (ROIC) was identified. These three accomplishments will allow the Sivananthan Laboratories team, with the help of the Guyot-Sionnest group at the University of Chicago, to develop a fully functional FPA during Phase II. The Guyot-Sionnest group will apply their substantial expertise to improve synthesis methods to create CQDs with the desired optical absorption and electrical properties in the 8-12 micron cutoff range at room temperature. The Sivananthan Laboratories group will leverage its extensive experience in nanotechnology, infrared technologies, device design and fabrication, as well as infrared camera design and hyperspectral imaging to build a low-cost LWIR camera and a hyperspectral imaging system.


Grant
Agency: Department of Defense | Branch: Missile Defense Agency | Program: STTR | Phase: Phase I | Award Amount: 149.98K | Year: 2011

Current state-of-the-art infrared focal plane arrays (IRFPAs) are based on HgCdTe material epitaxially grown on bulk CdZnTe substrates. The size of the IRFPAs is limited by the size of the available CdZnTe substrates and the thermal mismatch between CdZnTe and the Si readout circuit, which misaligns the photodiode array with respect to the circuit during heating and cooling cycles. Having HgCdTe fabricated on Si-based composite substrates would eliminate the aforementioned drawbacks related to the HgCdTe/CdZnTe system. Indeed, the use of Si-based substrates would also lower imager costs. While a large effort has been put forward to improve the quality of the HgCdTe grown on CdTe/Si, there still remains much room for further advancement. In the proposed effort, Episensors will develop new and innovative chemical mechanical polishing slurries and cleaning techniques that will yield higher quality Si(112) substrates. CdTe/Si layers will be grown in-house via molecular beam epitaxy and the growth of HgCdTe on CdTe/Si will take place at the University of Illinois at Chicago. We will employ advanced methods for characterizing the materials and devices to provide feedback for process optimization.


Grant
Agency: Department of Defense | Branch: Office for Chemical and Biological Defense | Program: SBIR | Phase: Phase I | Award Amount: 99.99K | Year: 2013

The primary goal of this proposed work is to develop a long wave infrared (LWIR) colloidal quantum dot (CQD)-based focal plane array (FPA) in order to significantly reduce the cost of LWIR hyperspectral imagers. In order to realize this goal, it will first be necessary to successfully fabricate and demonstrate the performance of novel LWIR HgTe CQD detector arrays. This will be accomplished through a collaboration between the Episensors Technologies team and Prof. Guyot-Sionnest"s group at the University of Chicago. The Episensors team will leverage its extensive experience in nanotechnology, infrared technologies, device design and fabrication to develop and test detector arrays utilizing HgTe CQD films as the IR absorber material. The Guyot-Sionnest group will apply their substantial expertise to develop synthesis methods for generating CQDs with good optical absorption and electrical properties in the 8-12 micron range. The LWIR CQD detector arrays will be fabricated and tested by the Episensors team. This synergistic effort will provide a high probably of success by utilizing both the chemical synthesis experience of the Guyot-Sionnest group and the IR device experience of the Episensors team.


Grant
Agency: Department of Defense | Branch: Missile Defense Agency | Program: STTR | Phase: Phase II | Award Amount: 999.99K | Year: 2013

In Phase I, Sivananthan Laboratories (SL) demonstrated the ability to polish Si(211) wafers, as supplied by a vendor with an already fine polish, to an even better surface smoothness and uniformity. SL also demonstrated the molecular beam epitaxy (MBE) growth of CdTe films with better crystalline quality and uniformity using SL-polished 2 cm x 2 cm Si(211) samples, compared to those grown on the vendor-polished Si(211) samples. In Phase II, we propose to scale up and optimize the chemo-mechanical polishing to deliver 3-inch epi-ready Si(211) substrates, which will require a minimum of pre growth processing on the part of the epilayer grower to produce a quality device layer with an area of 25 cm2. We will demonstrate CdTe and HgCdTe growth on 3-inch epi-ready Si(211) wafers with properties exceeding the current state of the art HgCdTe and CdTe films on Si. Using a variety of advanced nondestructive characterization tools, the surface chemistry associated with chemical polishing agents and etchants will be investigated for further optimization of our successful, proprietary chemical polishing protocols, which were developed during the Phase I program. Focal plane arrays (FPAs) will also be fabricated with HgCdTe grown on CdTe/Si layers and characterized to validate SL's polishing process.


Grant
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 125.00K | Year: 2016

We propose to advance the Ga-free InAs/InAsSb type II superlattice (T2SL) materials technology for very long wavelength infrared (VLWIR) focal plane arrays (FPAs) by passivating lifetime-limiting defects with hydrogen from inductively coupled plasma (ICP) H2-plasmas. In Phase II, 1k x 1k detector arrays will be fabricated and hybridized to matching read-out integrated circuits for implementation in future Earth and Planetary science infrared imaging instruments and become part of future space missions. Larger format FPAs (2k x 2k) will be realized as part of follow-up developments extending beyond Phase II. In Phase I, we will compute and optimize the electronic band structures, optical properties, Auger coefficients and ideal diffusion-limited dark currents of InAs/InAsSb T2SL absorber materials. The operating temperatures and overall thickness will be used as part of a trade-off study designed to achieve the quantum efficiency and dark current program goals. Shockley-Read-Hall minority carrier lifetimes of T2SLs are predicted to increase due to hydrogen-passivation, leading to larger signal-to-noise ratios for improved range of detection, enhanced discrimination capabilities, or operation at higher temperatures. Reducing the electrical activity of defects by passivating them with hydrogen is equivalent to lowering their density, and has proven successful in other semiconductor systems. The proposed hydrogenation technique makes use of the same dry-etch equipment employed during FPA manufacturing, making it easy to implement. In addition to the potential to remove the deleterious effects of bulk material defects, ICP hydrogenation also improves the detector's surface passivation quality. Smaller pixels, reduced integration times, and systems with larger fields-of-view will be realized, allowing the imaging of fast changing scenes over long ranges.


Grant
Agency: Department of Defense | Branch: Missile Defense Agency | Program: SBIR | Phase: Phase I | Award Amount: 123.34K | Year: 2015

Absorber layers based on Type-II superlattices (T2SLs) composed of III-V compound semiconductors (e.g. GaSb and InAs) are a promising sensor technology for infrared imaging; however, dark currents and short carrier lifetimes in the Ga-containing T2SL are significant problems. It is presently suspected that the short carrier lifetimes and some dark current arise due to a native point defect, possibly the Ga antisite (a Ga atom on the Sb sublattice), creating a mid-gap state within the T2SL band gap that facilitates Shockley-Read-Hall generation/recombination. We propose to use first principles calculations to verify the suspect defect and evaluate its impact on lifetimes and dark currents, and study its impact as a function of position within the superlattice period. Other native defects will also be examined. Molecular dynamics molecular beam epitaxy growth simulations will then be used to evaluate growth strategies that minimize the concentration of the key defects. Experiments will then be performed to verify the theoretical understanding and optimize a growth process based on the theoretical predictions. Approved for Public Release 14-MDA-8047 (14 Nov 14)


Grant
Agency: Department of Defense | Branch: Missile Defense Agency | Program: SBIR | Phase: Phase I | Award Amount: 99.79K | Year: 2015

We propose to develop a non-destructive test method to identify and quantify the formation of red plague corrosion within an insulated silver-plated copper wire. Cross-linked ethylene-tetrafluoroethylene (XL-ETFE)-insulated silver-plated copper wire demonstrates high performance and is commonly used in military and aerospace applications as hook-up and lead wire, but is prone to galvanic corrosion that can lead to unpredictable in-flight failures after only 10 years of life. There is currently no acceptable method to determine the extent of corrosion in a silver-plated copper wire. Our proposed approach for red plague corrosion detection is to transmit a well-defined signal through the wire and accurately measure the output signal. By employing sophisticated analysis techniques, we will identify the signature of red plague corrosion and quantitatively calibrate it with the extent of corrosion present in the wire. Our approach to the measurement and analysis provides the sensitivity needed to detect early stages of corrosion while reducing the potential for erroneous detection. With the proposed development of a highly-sensitive and accurate test method to quantitatively detect red plague corrosion within an insulated silver-plated copper wire, we will establish the foundation of a novel commercial test system. (Approved for Public Release 15-MDA-8482 (17 November 15))

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