Lattice mismatch and the nature of dissolution in the LPE of Pb-Salt compounds

It is shown experimentally that lattice matching is important in determining the nature of the solid/solution interface behavior during controlled meltback near saturation conditions. We define the lattice matching between a crystalline substrate and a solution via the solid in equilibrium with the solution and in a similar way lattice mismatch conditions can be defined as well. We found that a flat interface is preserved during meltback and regrowth if the solution is lattice matched to the substrate even when they are of different chemical potentials. Meltback and regrowth under matched conditions has been used to form graded-gap heterostructures with flat interfaces. We suggest using undersaturated lattice matched solutions whenever an in situ removal of the top part of a substrate is needed prior to epitaxial growth.