High detectivity InAs(0.85)Sb(0.15)/InAs infrared (1.8-4.8micron) detectors.

We report the operation of broad band InAs(0.80)Sb(0.15) pn junction photodetectors grown on InAs by liquid phase epitaxy. Despite the relatively large mismatch (~-1%) between the layers and the substrate, the devices exhibit excellent zero bias dectectivities [D(*) (70 K) = 1.5x10(11)cm(Hz)(1/2); D(*) over W (200 K) = 2x10(10)cm(Hz)(1/2) over W at lambda = 3.5micron] and peak external quantum efficiencies of 40%.