Two-dimensional MoSe2/graphene heterostructure thin film with wafer-scale continuity via van der Waals epitaxy

Two-dimensional MoSe2/graphene heterostructure in a wafer-scale was realized by a new method involves physical vapor deposition (PVD), in which the MoSe2 film was vertically stacked on graphene by evaporating the MoSe2 compounds using an electron gun evaporator. A preferred lattice orientation with the underlying graphene was identified by transmission electron microscopy, revealing the van der Waals epitaxy (VdWs) of MoSe2. The interface interaction between the graphene substrate and the MoSe2 epilayer was investigated via Raman spectroscopy. The growth technique provides a facile route to create large area VdWs heterostructures, which can be developed for future mass production of nano-devices.