Effect of MoO3 buffer layer on the electronic structure of Al–BP interface

The interfacial modification effect of the molybdenum trioxide (MoO3) buffer layer inserted between Al and black phosphorus (BP) was investigated with photoemission spectroscopy. The results show that MoO3 buffer layer can effectively prevent the destruction of the outermost BP lattice by Al thermal deposition and change the interface electronic structure between Al and BP. At the MoO3/BP interface, there is an interface dipole pointing from MoO3 to BP. During the metal deposition process, an interfacial chemical reaction between Al and MoO3 was found. These observations would provide insight for fabricating high-performance BP-based devices.