High quantum efficiency mid-wavelength interband cascade infrared photodetectors with one and two stages

In this paper, we report on mid-wavelength infrared interband cascade photodetectors grown on InAs substrates. We studied the transport properties of the photon-generated carriers in the interband cascade structures by comparing two different detectors, a single stage detector and a two-stage cascade detector. The two-stage device showed quantum efficiency around 19.8% at room temperature, and clear optical response was measured even at a temperature of 323 K. The two detectors showed similar Johnson-noise limited detectivity. The peak detectivity of the one- and two-stage devices was measured to be 2.15 × 10 14 cm·Hz 1/02 /W and 2.19 × 10 14 cm·Hz 1/02 /W at 80 K, 1.21 × 10 9 cm·Hz 1/02 /W and 1.23 × 10 9 cm·Hz 1/02 /W at 300 K, respectively. The 300 K background limited infrared performance (BLIP) operation temperature is estimated to be over 140 K.