Spectral crosstalk reduction in dual-band long-wavelength infrared (LWIR) photodetectors based on antimonide-based type-II superlattices

Antimonide-based Type-II superlattices (T2SL) are capable of delivering highly capable infrared detection capability. Improvement in material quality and processing techniques, as well as evolutionary modifications in device architecture have demonstrated the advantages of the material system over alternatives, and proven it as a viable candidate for the next generation infrared detection. Yet, the performance of this material system has not reached its limits. Further improvement in T2SL-based device performance is desired. One particular technical challenge limiting the utility of T2SL-based dual-band detectors is unwanted spectral crosstalk. Some potential sources of spectral crosstalk include: Incomplete optical absorption of photons at one absorber due to broadband peak width, low quantum efficiency in each absorber region, radiative recombination of carriers generated by photons at band one and emitting into band two, and flawed device barrier architecture. In this project, we propose to study the spectral crosstalk in strain-balanced antimonide-based type-II superlattices for dualband LWIR detection and imaging. At the end of this effort, we expect to minimize the spectral crosstalk in these devices while they demonstrate excellent electrical and optical performance. Approved for Public Release 16-MDA-8620 (1 April 16)