Reduction in dark current using resonant tunneling barriers in quantum dots-in-a-well long wavelength infrared photodetector

We report the use of resonant tunneling (RT) assisted barriers to reduce the dark current in quantum dots-in-a-well (DWELL) infrared photodetectors. Designed RT barriers allow energy-selective extraction of photoexcited carriers while blocking a continuum of energies. Over two orders of magnitude reduction in the dark current in the RT-DWELL device over a control sample without RT-DWELL at 77 K has been demonstrated. Specific detectivity ( D * ) of 3.6 × 10 9 cm Hz 1 ∕ 2 W − 1 at 77 K at λ peak = 11 μ m with a conversion efficiency of 5.3% was obtained in the RT-DWELL device. D * for the RT-DWELL device is five times higher than that of the control sample.