InSb quantum dots produced by liquid-phase epitaxy on InGaAsSb/GaSb substrates

Indium-antimonide quantum dots are for the first time formed on the surface of an epitaxial In0.25GaAsSb layer isoperiodic to a GaSb(001) substrate by liquid-phase epitaxy in the range of temperatures T = 450–467°C. Transmission electron microscopy shows that, the shape of quantum dots is close to a truncated cone and their distribution in terms of height and base size in the ensemble is monomodal. Large-sized quantum dots (with a base size of 30–50 nm and height of 3 nm) exhibit specific contrast in the plane-view diffraction-mode image, which is indicative of the presence of misfit defects. Modification of the chemical composition of the working surface of the substrate by the deposition of an epitaxial In0.25GaAsSb layer makes possible a threefold increase in the density of the ensemble of InSb quantum dots (1 × 1010 cm–2) compared to the density in the case of deposition directly onto the GaSb binary compound.