Ultrasharp interfaces grown with Van der Waals epitaxy

Van der Waals epitaxy, which we have recently developed, has opened a new way to fabricate many kinds of ultrathin heterostructures consisting of metals, semiconductors and insulators by using various transition metal dichalcogenide materials. It also has the advantage that a very sharp and defect-free interface is grown because of the non-existence of dangling bonds at the interface. In order to check the sharpness on the interface, non-destructive in-depth profiling has been done for the first time by low-energy electron loss spectroscopy in a MoSe2/MoS2 heterostructure made with van der Waals epitaxy and its interface has been proved to be as sharp as one monolayer.