Optimizing well doping density for GaAs/AlGaAs <i>p</i>-type quantum well infrared photodetectors

Abstract

Effects of well doping density on the performance of GaAs/AlGaAs p-type quantum well infrared photodetectors are systematically studied. We find that for devices covering the 3–5 μm wavelength region and operating at about 100 K, the optimum two-dimensional doping density is in the range 1–2×1012 cm−2, which maximizes the background limited infrared performance temperature and dark current limited detectivity. Increasing the doping density not only enhances the peak absorption but also broadens the linewidth pronouncedly.