Domain boundaries in incommensurate epitaxial layers on weakly interacting substrates

There has been increasing interest in the fabrication of thin film materials with mixed dimensions, in particular, 2D to 3D and 3D to 2D heterostructures. Often, if the interface interaction is weak, the lattice matching criterion between the substrate and overlayer can be lifted. If the overlayer lattice is completely relaxed, it can form an incommensurate film on the mismatched substrate. In this work, we show that domain boundaries are...