Normal-incidence InAs/In0.15Ga0.85As quantum dots-in-a-well detector operating in the long-wave infrared atmospheric window (8–12 μm)

Normal incidence InAs/In0.15Ga0.85As dots-in-a-well (DWELL) detectors are reported in which the peak operating wavelength was tailored from 7.2 to 11 μm using heterostructure engineering of the DWELL structure. Using an optimized design, a detector with a spectral response spanning the long-wave infrared atmospheric window (8–12 μm) is obtained. Spectral response peaks were observed at λp=10.3 μm and 11.3 μm under positive and negative bias, respectively. These peaks are attributed to bound-to-bound transitions from the InAs quantum dot to the InGaAs well.