Investigation of Si-doped p-type AlGaAs/GaAs, AlGaAs/InGaAs quantum well infrared photodetectors and multiquantum wells grown on (311)A GaAs

We have studied two Si-doped p-type quantum well infrared photodetectors (QWIPs) using AlGaAs/GaAs and AlGaAs/InGaAs grown on (3 1 1)A GaAs. The Si-doped AlGaAs/GaAs p-QWIP exhibits a symmetrical dark I-V characteristic at all the measured temperatures from 40 to 120 K. The strained p-type AlGaAs/InGaAs QWIP exhibits a slightly asymmetrical dark I-V characteristic, but is markedly less asymmetrical than that doped with beryllium. The slight asymmetry in dark I-V characteristic and the large blue-shift in responsivity spectra may be due to the thickness modulation observed from TEM and the red-shift of PL peak energy, where PL peak energies from (3 1 1)A AlGaAs/InGaAs multiple quantum wells are red-shifts of 7 and 22 meV to the side-by-side grown (1 0 0).