Uncooled InAs-GaSb type-II infrared detectors grown on GaAs substrates forthe 8-12-mu m atmospheric window

We report on the growth and characterization of type-e infrared detectors w ith an InAs-GaSb superlattice active layer for the 8-12-mu m atmospheric wi ndow at 300 K, The material was grown by molecular beam epitaxy on semi-ins ulating GaAs substrates. Photoconductive detectors fabricated from the supe rlattices showed 80% cutoff at about 12 mu m at room temperature. The respo nsivity of the device is about 2 mA/W with a 1-V bias (E = 5 V/cm) and the maximum measured detectivity of the device is 1.3 x 10(8) cm.Hz(1/2)/W at 1 1 mu m at room temperature. The detector shows very weak temperature sensit ivity. Also, the extracted effective carrier lifetime, tau = 26 ns, is an o rder of magnitude longer than the carrier lifetime in HgCdTe with similar b andgap and carrier concentration.