Broadband staircase quantum well infrared photodetector with low dark current

We present a theoretical investigation of a novel staircase-like quantum well infrared photodetector (QWIP). It detects wavelengths between 8.8 μm and 12.3 μm at an applied electric field of F = 6 × 104 V/cm at room temperature. Device operation is based on inter-subband bound to continuum transition. We also calculated the responsivity at room temperature and dark current density at 77 K. The dark current density was found to be around 10−8 A/cm2 at operating bias, which is lower than the conventional QWIPs in the literature.