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Design of III-V Antimonide InAs/InAsSb Strained-Layer Superlattice Materials for Improved LWIR Performance




OBJECTIVE: Develop minority carrier transport model software based on innovative electronic structure and transport models leading to superior nBn InAs/InAsSb antimonide-based strained-layer superlattice materials. 


DESCRIPTION: For III-V infrared focal plane arrays for mid-wavelength infrared (MWIR) and long wavelength infrared (LWIR) imaging, InAs/InAsSb strained-layer superlattice materials using unipolar barrier device structures are a promising technology. The use of such superlattices increases the minority carrier lifetime dramatically over Ga-containing antimonide materials to be comparable with HgCdTe but also introduces numerous barriers to minority carrier transport. These barriers disrupt carrier transport, either intrinsically or through the introduction of additional roughness to the barriers. To this point, modern high-accuracy transport calculations do not utilize the electronic structure of the full superlattice material. 


PHASE I: Develop a model that can integrate the superlattice electronic structure calculations used for optical absorption, Auger recombination, defect scattering, and other design criteria, with an accurate transport calculation suitable for operating temperatures and doping ranges of interest for such detectors. Deliver initial prototype model and software code for scientific validation. 


PHASE II: Develop the model into a prototype software product that can be reliably used with limited expertise. Demonstrate use of the software to predict vertical transport carrier mobilities and, when combined with carrier lifetime calculations, to predict quantum efficiencies and detectivities. Deliver prototype model software for verification with experimental results. 


PHASE III: Further develop the software product to be generic for any III-V material superlattice design, making it widely applicable for commercial and defense emitter and detector applications in any wavelength range. 



1: E. H. Steenbergen, B. C. Connelly, G. D. Metcalfe, H. Shen, M. Wraback, D. Lubyshev, J. M. Fastenau, A. W. K. Liu, S. Elhamri, O. O. Cellek, and Y.-H. Zhang, Appl. Phys. Lett. 99, 251110 (2011).

2:  B. V. Olson, L. M. Murray, J. P. Prineas, M. E. Flatte , J. T. Olesberg, and T. F. Boggess, Appl. Phys. Lett. 102, 202101 (2013).

3:  Y. Aytac, B. V. Olson, J. K. Kim, E. A. Shaner, S. D. Hawkins, J. F. Klem, M. E. Flatte , and T. F. Boggess, J. Appl. Phys. 118, 125701 (2015).



KEYWORDS: Infrared, Superlattice, Detector, Transport, Model, Software 


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