Low Crosstalk Three-Color Infrared Detector by Controlling the Minority Carriers Type of InAs/GaSb Superlattices for Middle-Long and Very-Long Wavelength

We report a type-II InAs/GaSb superlattice three-color infrared detector for mid-wave (MW), long-wave (LW), and very long-wave (VLW) detections. The detector structure consists of three contacts of NIPIN architecture for MW and LW detections, and hetero-junction NIP architecture for VLW detection. It is found that the spectral crosstalks can be significantly reduced by controlling the minority carriers transport via doping beryllium in the two active regions of NIPIN section. The crosstalk detection at MW, LW, and VLW signals are achieved by selecting the bias voltages on the device. At 77 K, the cutoff wavelengths of the three-color detection are 5.3 μm (at 0 mV), 14 μm (at 300 mV) and 19 μm (at -20 mV) with the detectivities of 4.6\times10^11 cm\cdotHz^1/2W^-1, 2.3\times10^10 cm\cdotHz^1/2W^-1, and 1.0\times10^10 cm\cdotHz^1/2W^-1 for MW, LW and VLW. The crosstalks of the MW channel, LW channel, and VLW channel are almost 0, 0.25, and 0.6, respectively.