High Performance Noise-Suppressing Long Wavelength Infrared Mercury Cadmium Telluride Focal Plane Array (FPA) Sensors

We propose the development of long wavelength infrared (LWIR) sensors based on HgCdTe in a novel noise-suppressing high temperature barrier (HTB) architecture, which combines the benefits of unipolar nBn and non-equilibrium, Auger-suppressing high operating temperature (HOT) structures. The proposed design is beneficial for controlling carrier conduction to minimize the number of majority and minority carriers flowing from the contacts into the absorber without relying on minority carrier diffusion length limitations alone. The reduction in the numbers of minority and majority carriers entering the absorber region is necessary to reduce thermal generation-recombination processes facilitated by high carrier concentrations; this is particularly relevant for LWIR detectors which are more susceptible to performance degradation due to high thermal noise. This proposed effort will focus on three primary tasks: 1) carry out simulations of LWIR HgCdTe HTB device architectures, 2) fabricate and characterize single element LWIR HgCdTe HTB photodetectors with spectral response out to 12 m at temperatures above 70 K based on epitaxially-grown HgCdTe heterostructures, and 3) should this effort progress to Phase II, then HTB LWIR HgCdTe focal plane arrays will be fabricated in a 640 x 512 format. Approved for Public Release 14-MDA-8047 (14 Nov 14)