Growth and characterization of van der Waals heterostuctures formed by the topological insulator Bi2Se3 and the trivial insulator SnSe2

The formation, structure and electronic properties of SnSe2–Bi2Se3 van der Waals heterostructures were studied. Both heterostructures, SnSe2 on Bi2Se3 and Bi2Se3 on SnSe2, were grown epitaxially with high crystallinity and sharp interfaces. Their electron band structures are of trivial and topological insulators, respectively. The Dirac surface states of Bi2Se3 survive under the SnSe2 overlayer. One triple layer of SnSe2 was found to be an efficient spacer for separating a Bi2Se3 topological-insulator slab into two and creating the corresponding topological surface states.