Demonstration of high performance bias-selectable dual-band short-/mid-wavelength infrared photodetectors based on type-II InAs/GaSb/AlSb superlattices

High performance bias-selectable dual-band short-/mid-wavelength infrared photodetector based on InAs/GaSb/AlSb type-II superlattice with designed cut-off wavelengths of 2 mu m and 4 mu m was demonstrated. At 150 K, the short-wave channel exhibited a quantum efficiency of 55%, a dark current density of 1.0 x 10(-9) A/cm(2) at -50mV bias voltage, providing an associated shot noise detectivity of 3.0 x 10(13) Jones. The mid-wavelength channel exhibited a quantum efficiency of 33% and a dark current density of 2.6 x 10(-5) A/cm(2) at 300mV bias voltage, resulting in a detectivity of 4.0 x 10(11) Jones. The spectral cross-talk between the two channels was also discussed for further optimization. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773593]