Instability of homogeneous composition of highly strained QWs in heterostructures GaAs/In/sub x/Ga/sub 1-x/As/GaAs

In/sub x/Ga/sub 1-x/As QW-layers embedded in GaAs matrix have been characterized by photoluminescence (PL) study. We have established the relation between the PL parameters and mismatch of the lattice parameters of the layer and matrix. In highly strained layers several PL bands were observed instead of one band. This was shown to be a result of alternating content of In arised only in highly strained layers.