TEM-study of free-standing self-assembled InSb quantum dots grown on InAs surface

We have investigated the morphology of free-standing self-assembled InSb quantum dots (QDs) grown by liquid-phase epitaxy (LPE) under conventional growth conditions on InAs(0 0 1) substrate. Two growth modes, Volmer-Weber for low-density (5 × 108 cm−2) large QDs with 10-12 nm in a height and Stranski-Krastanow for high-density (1 × 1010 cm−2) small QDs with a height of 3-4 nm, were identified in dependence on a critical growth temperature of InSb QDs formation. Characterization of the sample surface was performed using transmission electron microscopy (TEM) that allowed us to observe some features of the InSb QD shape which transforms from a full dome to truncated one with increasing QD lateral size from 15 to 40 nm, respectively. Using pseudo-moiré pattern appearing in plan-view diffraction TEM image the critical size of the InSb QD for plastic deformation was evaluated.

► We studied the morphology of self-assembled InSb QDs free-standing on InAs surface. ► Characterization by TEM of the single InSb QD was performed for the first time. ► We can evaluate the size of the InSb QD using moire pattern in plan-view image.