Interfacial interaction in monolayer transition metal dichalcogenides (MX2)/metal oxide heterostructures and its effects on electronic and optical properties: The case of MX2/CeO2

摘要

Two-dimensional transition metal dichalcogenides (MX2)/metal oxideheterostructures have shown unique physical properties, making them promisingmaterials for various applications ranging from photocatalysis to solar energyconversion. Understanding the interfacial interactions is highly desirable fordesigning these heterostructures having excellent performance. Here wesystematically study the interfacial interaction in monolayer MX2 (M=Mo, W;X=S, Se)/CeO2 heterostructures and its effects on electronic and opticalproperties by density functional theory. It is found that the interfacialinteraction in the MX2/CeO2 depends predominantly on the chalcogen (X) element.Particularly, the band gap variation and important electronic states atconduction band minimum or valence band maximum of the heterostructures aredetermined by the strength of interfacial interaction. The MX2/CeO2heterostructures with the same chalcogen (X) element have similar absorptionspectra from ultraviolet to near-infrared regions. These results suggest thatthe chalcogen (X) element is a key factor in tuning the properties of MX2/metaloxide heterostructures.