High Performance Mwir Type-Ii Superlattice Detectors

A VGA format type-II superlattice focal plane array (FPA) for the mid-wave infrared (MWIR) atmospheric window has been designed, manufactured and characterized. The detector material is based on a heterojunction structure with a barrier that effectively decreases the Shockley-Read-Hall based component of the dark current. A very effective passivation method has been used which successfully inhibits all surface leakage currents. The barrier structure has a 50 % cutoff at 5 mu m and 65 % quantum efficiency without antireflective coating. The dark current density is 3x10(-6) A/cm(2) at -0.05 V bias and 120 K. The optical cavity of the detector has been optimized for maximum capture of available light in the MWIR window. A focal plane array with 640 by 512 pixels and 15 mu m pitch was processed based on this barrier structure. High-quality imagery in a system with high F-number will be presented.