Long-wavelength infrared photodetectors based on InSbBi grown on GaAs substrates

We demonstrate the operation of InSbBi infrared photoconductive detectors grown by low-pressure metalorganic chemical vapor deposit ion on semi-insulating GeAs substrates, The fabricated photodetector showed a cutoff wavelength of 7.7 mu m at 77 K. The responsivity of the InSbBi photodetector at 7 mu m was about 3.2 V/W at 77 K. The corresponding Johnson-noise limited detectivity was 4.7 X 10(8) cm Hz(1/2)/W. The carrier lifetime was estimated to be about 86 ns from the voltage-dependent responsivity measurements. (C) 1997 American Institute of Physics.