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 x 10(9) cm Hz(1/2) W(-1) at 77 K at lambda(peak) 11 mu 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. (C) 200