Effect of thin intermediate-layer of InAs quantum dots on the physical properties of InSb films grown on (001) GaAs

In this study the formation of a semiconducting InSb layer, preceded by the growth of an intermediate layer of InAs quantum dots, is attempted on (001) GaAs substrate. From the analysis of atomic-force-microscopy and transmission-electron-microscopy images together with Raman spectra of the InSb films, it is found that there exists a particular layer-thickness of ~ 0.5 μm above which the structural and transport qualities of the film are considerably enhanced. The resultant 2.60-μm-thick InSb layer, grown at the substrate temperature of 400 °C and under the Sb flux of 1.5 × 10− 6 Torr, shows the electron mobility as high as 67,890 cm2/Vs.

► InSb films are grown on GaAs substrate by molecular beam epitaxy.
► Intermediate layer of InAs quantum dots is inserted at GaAs/InSb interface.
► Structural and transport properties of InSb are enhanced with InAs quantum dots.
► Electron mobility over 50,000 cm2/Vs is achieved within 1-μm thickness of InSb.