Advanced InAs/GaSb superlattice photovoltaic detectors for very long wavelength infrared applications

We report on the temperature dependence of the photoresponse of very long wavelength infrared type-II InAs/GaSb superlattice based photovoltaic detectors grown by molecular-beam epitaxy. The detectors had a 50% cutoff wavelength of 18.8 mum and a peak current responsivity of 4 A/W at 80 K. A peak detectivity of 4.5x10(10) cm Hz(1/2)/W was achieved at 80 K at a reverse bias of 110 mV. The generation-recombination lifetime was 0.4 ns at 80 K. The cutoff wavelength increased very slowly with increasing temperature with a net shift from 20 to 80 K of only 1.2 mum. (C) 2002 American Institute of Physics.