van der Waals (vdW) heterostructures, which combine bidimensional materials of different properties, enable a range of quantum phenomena. Herein, we present a comparative study between the electronic properties of mono- and bilayer of platinum diselenide (PtSe2) grown on hexagonal boron nitride (h-BN) and graphene substrates using molecular beam epitaxy (MBE). Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), the electronic structure of PtSe2/graphene and PtSe2/h-BN vdW heterostructures is investigated in a systematic manner. In contrast to PtSe2/h-BN, the electronic structure of PtSe2/graphene reveals the presence of interlayer hybridization between PtSe2and graphene, which is evidenced by minigap openings in the π-band of graphene. Furthermore, our measurements show that the valence band maximum (VBM) of monolayer PtSe2is located at the Γ point with different binding energies of about −0.9 and −0.55 eV relative to the Fermi level on h-BN and graphene and substrates, respectively. Our results represent a significant advance in the understanding of electronic hybridization between TMDs and different substrates, and they reaffirm the crucial role of the substrate in any nanoelectronic applications based on van der Waals heterostructures.
