Longwave infrared focal plane arrays from type-II strained layer superlattices

We report high quantum efficiency low-noise longwave infrared focal plane arrays (FPAs) made from type-II InAs/GaSb strained layer superlattice (SLS) photodiodes. In 320 × 256 FPAs operating at 77 K, we measure cutoff wavelength ∼8.5 μm, dark current density ∼10−4 A/cm2, average conversion efficiency ∼50% (with 2 μm-thick absorber photodiode), and temporal noise equivalent difference in temperature (NEDT) <20 mK at F/4.