PbSnTe based long-wave infrared (LWIR) focal plane arrays (FPAs)

Structured Materials Industries, working with an experienced infrared focal plane array (IR-FPA) developer, will research and develop lead tin telluride (PbSnTe) or (PTT) based long-wave infrared (LWIR) focal plane arrays (FPAs) with the objective of demonstrating that the performance of PTT can exceed the current HgCdTe (MCT) or III-V superlattice LWIR-FPAs i.e increased Quantum Efficiency, lower dark current at 77K and higher sensitivity for short (e.g. milliseconds) integration times. PTT has shown great promise to meet and exceed MCT performance and cost; however sufficient effort to resolve its true potential remains to be realized. Enhancing this work’s success potential is that SMI has developed an epitaxial growth process for PbTe on Si for making MWIR and LWIR metalenses – furthering the development of an alternative to MCT on very large substrates. In Phase I, we will review material properties, grow crystals (doped and undoped), and test sensor “pixel” performance designs, characterizing the grown materials, fabricate simple detector “pixels”, and refine our Phase II plan – to produce simple demonstration-scale multiple pixels LWIR-FPAs that can be sampled to appropriate end-user partners. The program will determine the scientific and technical Phase III feasibility of implementing increasingly scaled PPT LWIR-FPAs. Approved for Public Release | 21-MDA-11013 (19 Nov 21)