Fig. 1. Schematic drawing of the band structure of the detector

Fig. 2. The dark current density curves from 77 K to 300 K

Fig. 3. The Arrhenius plot of the measured dark current density between 77 K and 300 K

Fig. 4. The responsivity and the detectivity D^⋆ of the device from 77 K to 300 K when the bias voltage is 0 V

Fig. 5. The peak dark current（I_P），the valley dark current（I_V），and the peak-to-valley current ratio（PVCR）from 77 K to 220 K