Photoluminescence study of InGaAs/AlAsSb heterostructure

InGaAs/AlAsSb quantum well structures have been grown by molecular beam epitaxy nominally lattice matched to InP substrates and characterized by photoluminescence. Growth interruptions at interfaces combined with selective group V species exposure were used. Our results indicate that interface quality: interface roughness as well as compositional variations involving group V sublattice species intermixing determine the nature of band alignment at heterointerfaces. The type I band lineup with band-edge discontinuity was estimated to be about 1.6 eV for As-terminated samples, which exhibit the lowest compositional fluctuations across heterointerfaces. The photoluminescence linewidths from InGaAs/AlAsSb quantum wells agree with linewidths calculated on the assumption of 1 ML fluctuations in well width. The inhomogeneous nature of the intermixed layers results in a large broadening of the luminescence spectra line shape for samples grown without termination or Sb termination. (C) 2001 American Institute of Physics.