Mid-infrared metamorphic interband cascade photodetectors on GaAs substrates

Antimony-based mid-infrared interband cascade (IC) photodetectors fabricated on ( 001) GaAs substrates are reported. By using a buffer-free interfacial misfit array growth method, an overall good crystalline quality is obtained on the largely lattice-mismatched GaAs substrate. The GaAs-based IC detectors show comparable optical performance, with similar electrical performance at temperatures higher than 140 K, as compared to the reference devices grown on GaSb substrate. The GaAs-based IC detectors demonstrate dark current density of 2.63 x 10(-6) A/cm(2) at 180 K, which is about twice as compared to that grown on GaSb substrate, with Johnson-limited D* of 1.06 x 10(11) Jones at 180K and 4.0 mu m. The results indicate that IC detector design is robust and relatively insensitive to the material quality, and metamorphic IC detector is viable for large-format infrared focal plane array applications. (C) 2015 AIP Publishing LLC.