Very long wavelength infrared type-II detectors operating at 80 K

We report a demonstration of very long wavelength infrared detectors based on InAs/GaSb superlattices operating at T=80 K. Detector structures with ex cellent material quality were grown on an optimized GaSb buffer layer on Ga As semi-insulating substrates. Photoconductive devices with 50% cutoff wave length of lambda(c)=17 mu m showed a peak responsivity of about 100 mA/W at T=80 K. Devices with 50% cutoff wavelengths up to lambda(c)=22 mu m were d emonstrated at this temperature. Good uniformity was obtained over large ar eas even for the devices with very long cutoff wavelengths. (C) 2000 Americ an Institute of Physics. [S0003-6951(00)00637-9].