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

Abstract

Indium-antimonide quantum dots are for the first time formed on the surface of an epitaxial In_0.25GaAsSb 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 In_0.25GaAsSb 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.