Performance of dual-band short- or mid-wavelength infrared photodetectors based on InGaAsSb bulk materials and InAs/GaSb superlattices

In this paper, we demonstrate bias-selectable dual-band short- or mid-wavelength infrared photodetectors based on In_0.24Ga_0.76As_0.21Sb_0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2.2 μm and 3.6 μ m, respectively. At 200 K, the short-wave channel exhibits a peak quantum efficiency of 42% and a dark current density of 5.93×10^-5 A/cm² at 500 mV, thereby providing a detectivity of 1.55×10¹¹ cm·Hz^1/2/W. The mid-wave channel exhibits a peak quantum efficiency of 31% and a dark current density of 1.22×10^-3 A/cm² at -300 mV, thereby resulting in a detectivity of 2.71×10¹⁰ cm·Hz^1/2/W. Moreover, we discuss the band alignment and spectral cross-talk of the dual-band n-i-p-p-i-n structure.