X-Ray Photoelectron Spectroscopy Study of 2D MoS2/Oxide Dielectric Interface

The interface between two-dimensional transition metal dichalcogenide (2D TMDs) semiconductors and dielectric has not been as widely studied as the metal/2D TMD junction. The dielectric for 2D TMD devices must be thermodynamically and mechanically stable as well as being chemically inert. The band offset between the conduction and valence bands of the dielectric and 2D semiconductor should be at least 1eV. The 2D TMD/dielectric interface should be clean and free of defects. In this presentation, we present detailed synchrotron XOS study of 2D TMD and oxide interface. Specifically, we have studied the band offsets between MoS₂ and SiO₂, HfO₂, and ZrO₂ using XPS. We find that the dielectrics strongly dope the 2D MoS₂ with significant shift (>1eV) in the Fermi level. Our results provide insight into suitability of different dielectrics for 2D MoS₂FETs.