We have used a direct x-ray phasing method, coherent Bragg rod analysis, to obtain sub-
angstrom resolution electron density maps of the InAs/GaAs dot system. The dots were
grown by the droplet heteroepitaxy (DHE) technique and their structural and compositional
properties are compared with those of dots grown by the strain-driven Stranski–Krastanov
method. Our results show that the Ga diffusion into the DHE-grown dots is somewhat larger;
however, other characteristics such as the composition of the dots' uppermost layers, the …