Uncooled InAs-GaSb type-II infrared detectors grown on GaAssubstrates for the 8-12-Μm atmospheric window

摘要

We report on the growth and characterization of type-II infraredndetectors with an InAs-GaSb superlattice active layer for the 8-12-Μmnatmospheric window at 300 K. The material was grown by molecular beamnepitaxy on semi-insulating GaAs substrates. Photoconductive detectorsnfabricated from the superlattices showed 80% cutoff at about 12 Μm atnroom temperature. The responsivity of the device is about 2 mA/W with an1-V bias (E=5 V/cm) and the maximum measured detectivity of the devicenis 1.3×108 cm.Hz1/2/W at 11 Μm at roomntemperature. The detector shows very weak temperature sensitivity. Also,nthe extracted effective carrier lifetime, Τ=26 ns, is an order ofnmagnitude longer than the carrier lifetime in HgCdTe with similarnbandgap and carrier concentration