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

Effects of well doping density on the performance of GaAs/AlGaAs p-type qua ntum well infrared photodetectors are systematically studied. We find that for devices covering the 3-5 mu m wavelength region and operating at about 100 K, the optimum two-dimensional doping density is in the range 1-2x10(12 ) cm(-2), which maximizes the background limited infrared performance tempe rature and dark current limited detectivity. Increasing the doping density not only enhances the peak absorption but also broadens the linewidth prono uncedly. (C) 1999 American Institute of Physics. [S0021-8979(99)06621-9].