| Summary: | We report on the growth of an InAs0.32Sb0.68 layer on (001) GaAs substrates. The lattice mismatch strain between the InAs0.32Sb0.68 layer and the GaAs substrate was accommodated using a thin 50–100 nm Ga0.35In0.65Sb buffer with interfacial misfit (IMF) dislocations. The epitaxial structures were characterized using transmission electron microscopy and x-ray diffraction analysis. The threading dislocation density in the InAs0.32Sb0.68 layer was reduced successfully to ∼1 × 108 cm−2 using the combination of a Ga0.35In0.65Sb IMF buffer and InSb/Ga0.35In0.65Sb superlattice layers. Compared to GaSb/GaAs and InSb/GaAs interfaces, a significantly higher threading dislocation density (>1011 cm−2) was observed at the Ga0.35In0.65Sb/GaAs interface. Detailed analysis suggests that high threading dislocation density in the Ga0.35In0.65Sb IMF buffer could be due to the non-uniform microscopic distribution of indium and gallium atoms. This work is beneficial to the scientific community in the growth of the InAs0.32Sb0.68 material as it provides a novel approach to prepare a platform for the growth of the InAs0.32Sb0.68 material, which does not have a suitable lattice-matched substrate, on the widely available GaAs substrate.
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