Investigation of a $p$–$i$–$n$ photodetector with an absorbing medium based on InGaAs/GaAs quantum well-dots

The static and dynamic characteristics of waveguide photodetectors with an absorbing region based on InGaAs/GaAs quantum well-dots were studied at room temperature. The absorption band of InGaAs/GaAs quantum well-dots is in the spectral range from 900 to 1100 nm. The waveguide photodetectors have a width of 50 $\mu$m and a length of the absorbing region from 92 $\mu$m to 400 $\mu$m. A low dark current density (1.1 and 22 $\mu$A/cm$^2$ at -1 and -20 V) and cut off frequency of 5.6 GHz, limited by the time constant of a parasitic equivalent electric RC-circuit, were obtained.