Effects of Si doping on normal incidence InAs∕In0.15Ga0.85As dots-in-well quantum dot infrared photodetectors

The effects of doping on InAs∕In0.15Ga0.85As quantum dots-in-well infrared photodetectors have been studied by measuring the dark current, photocurrent, and spectral response. A significant reduction of dark current with decrease in doping concentration in the quantum dots has been observed. However, the photocurrent of the detectors increases with the doping. By measuring the background limited infrared photodetector temperature, we find that the optimum sheet doping concentration in these detectors is n=3×1010cm−2 (corresponding to about one electron per dot).