Structural and optical properties of InSb epitaxial films grown on GaAs(100) substrates at low temperature

Abstract

Transmission electron microscopy (TEM) and reflectance measurements were carried out to investigate the structural and the optical properties of the InSb/GaAs heterostructures grown at low temperature (∼290 °C) for the possible use in fabricating CdTe/InSb quantum structures on GaAs substrates. X-ray diffraction measurements showed that the grown InSb layer was an epitaxial film, and TEM measurements indicated that the lattice mismatch between InSb and GaAs generated the formation of plane defects in the InSb epilayer near the InSb/GaAs heterointerface. When a 0.2 μm InSb layer was grown on the GaAs substrate, the InSb layer could be used as a defect-free substrate. Reflectance measurements showed the InSb longitudinal optical phonon. Structural and optical properties of the InSb/GaAs heterostructures were strongly affected by the growth temperature. These results indicate that the InSb buffer layer grown at low temperature, by eliminating the defects due to the lattice mismatch, plays an important role in the growth of CdTe/InSb quantum structures on GaAs substrates.