Impurity photoconductivity in strained p -InGaAs/GaAsP heterostructures

The impurity-photoconductivity spectrum is observed for strained quantum wells of the p-InGaAs/GaAs solid solution at T= 4.2 K. In addition to the broad photoconductivity band attributed to the transitions from the acceptor ground state to the continuum of the first size-quantization subband, the spectrum exhibits a peak due to the transitions from the ground state to the excited localized acceptor state, a band corresponding to the transitions to the resonance states associated with the second heavy-hole size-quantization subband, and a narrow photoconductivity peak (Fano resonance) in the spectral range corresponding to the optical-phonon energy.