RT&L FOCUS AREA(S): Directed energy TECHNOLOGY AREA(S): Sensors OBJECTIVE: Design and develop an advanced uncooled or thermoelectric (TE) cooled high performance wide band mid-wave infrared (MWIR) sensor at 5 m and a long-wave infrared sensor (LWIR) at > 8 um, compact imaging sensors that will be cost-effective and smaller than current night vision infrared (MWIR-LWIR) imaging systems available. DESCRIPTION: Imaging at MWIR (4-6 m) and LWIR (8 12 m) wavelengths is challenging because the bandgap of the semiconductor material is close to the thermal energy at room temperature. Current detection and imaging technologies in broadband sensors that cover the 5 to 12 m regime have to operate at cryogenic temperatures of 77 K or less in order to overcome the limitations of thermally generated noise. This requires expensive and bulky cooling systems that increase the overall size, weight, and power (SWaP) of imagers in MWIR/LWIR regime. The dominant technologies in this region are uncooled detector technology based on Silicon Carbide (SiC), amorphous silicon (aSi) and vanadium oxide (VOx) and cooled detector technology based Mercury (Hg)-Cadmium (Cd) Telluride (Te) (MCT known as HgCdTe) compounds, as well as the more recent type-II superlattices. Conventional Focal Plane Array (FPA) fabrication methods are complex and often require complicated photodetector array hybridization onto Silicon-based Read on Integrated Circuits (ROIC), which reduces the final yield, increases the overall cost significantly, and limits the application. Consequently, there exists a demand for migration to an alternative technology for LWIR detection that can address the following two fundamental challenges: High-performance uncooled/TE cooled operation and a simple/cost-effective integration at the wafer-scale with commercial ROICs. Also, current MWIR sensor cost is in the order of $50 to $100k with < 6000 hours of lifetime operation. The major drawback of these MWIR sensors is their employment of the stirling cryo cooling pump to improve imaging performance. One of the innovative approaches the Navy is interested in to overcome the physical limitations of bulky MWIR/LWIR photodetectors is the application of functionalized low-dimensional nanostructures, e.g., quantum wires and dots. These nanostructures incur favorable properties for high-performance uncooled detection, such as a higher absorption coefficient, elimination of phonon-assisted excitation (phonon bottleneck), and lower mean kinetic energy per particle. Quantum dot (0D) Nanostructures or 1D (one-dimension) nanowire structure offer three main advantages, as compared to conventional bulk- or thin film-based devices. They permit enhanced absorption of radiation by extending the absorption cross-section beyond the geometric footprint of a single nanostructure. The proposed topic shall not be limited to any of the technologies described in this Description; the Navy is looking for any new advanced next generation broadband high performance TE cooled or uncooled FPA for this application. This proposed technology will be used to enhance all Navy systems requiring precision optical verification and identification of subjects of interests. The smaller form factor enables employment in unmanned autonomous systems (UxV), and integration with non-organic sensors. PHASE I: Provide an innovative concept for a broadband (MWIR-LWIR) FPA sensor modeling, design, epitaxial growth, fabrication, and characterization of MWIR/LWIR broad band photodetectors based on quantum dot (0D), nanowire (1D), or nanostructure-contained quantum disks based on aSi, VOx, MCT, or any new next generation technology for uncooled or TE cooled high-performance MWIR/LWIR photo-detection. The Phase I Option, if exercised, will include the initial design specifications and capabilities description for the ground fault detection and localization system and develop a test plan and test procedures for the prototype developed in Phase II. PHASE II: Based on successful Phase I modeling results and the Phase II Statement of Work (SOW), in Phase II the company shall process wafer-scale integration of the MWIR/LWIR devices with readout integrated circuit (ROIC) and making TE cooled high-performance MWIR/LWIR focal plane array as described in the Description. Deliver the prototyped MWIR-LWIR FPA to the Navy for the sensor evaluation at a Navy facility to measure the imaging performance, Noise equivalent temperature, noise equivalent power, and detectivity of the sensor. PHASE III DUAL USE APPLICATIONS: Assist the Navy in transitioning the technology to Navy use (undersea and surface) and shall focus on large area (wafer scale) integration of high-density 0D nanostructure-contained quantum disks thin film for fabrication of TE cooled high-performance MWIR/LWIR photodetectors for device area greater than 100cm2 and quantum efficiencies greater than 50%. Demonstration of uncooled 320 256 MWIR/LWIR FPAs based on integration of sensors with commercially available ROICs. Specific industry applications are in the automobile, aerospace, and oil & gas industries. REFERENCES: Nguyen, B. M.; Hoffman, D.; Huang, E. K. W.; Delaunay, P. Y. and Razeghi, M. Background limited long wavelength infrared type-II InAs/GaSb superlattice photodiodes operating at 110 K. Applied Physics Letters, 93(12), 123502, 2008. https://aip.scitation.org/doi/10.1063/1.2978330 Yamanaka, T.; Movaghar, B.; Tsao, S.; Kuboya, S.; Myzaferi, A. and Razeghi, M. Gain-length scaling in quantum dot/quantum well infrared photodetectors. Applied Physics Letters, 95(9), 093502, 2009. https://aip.scitation.org/doi/10.1063/1.3222856 Pour, S. A.; Huang, E. W.; Chen, G.; Haddadi, A.; Nguyen, B. M. and Razeghi, M. High operating temperature midwave infrared photodiodes and focal plane arrays based on type-II InAs/GaSb superlattices. Applied Physics Letters, 98(14), 143501, 2011. https://aip.scitation.org/doi/10.1063/1.3573867 Haddadi, A.; Dehzangi, A.; Chevallier, R.; Adhikary, S. and Razeghi, M. Bias selectable nBn dual band long /very long wavelength infrared photodetectors based on InAs/InAs 1- x Sb x/AlAs 1- x Sb x type II superlattices. Scientific Reports, 7(1), Article Number: 3379, 2017. https://www.nature.com/articles/s41598-017-03238-2
