Band alignment of monolayer MoS2/4H-SiC heterojunction via first-principles calculations and x-ray photoelectron spectroscopy

摘要

2D/3D heterostructures have received extensive attention due to their unique structures and outstanding properties. In this work, the structural and electronic properties of monolayer MoS2/4H-SiC(Si-face) heterojunctions are systematically investigated through density functional theory calculation and experimental analysis. The calculated results show that the monolayer MoS2/4H-SiC heterostructure is a van der Waals heterojunction because of low formation energy and shows a type-II band alignment with a valence band offset of 1.43 eV. Then the type-II band alignment of the MoS2/4H-SiC heterostructure is verified by x-ray photoelectron spectroscopy. However, there is a deviation of 0.44 eV in the valence band offset between the calculated results and the experimental data, which may be caused by the underestimation of the bandgap by the Perdew-Burke-Ernzerhof method and the introduction of impurities at the interface. Our experimental results reveal the type of band alignment and the combination of the MoS2/4H-SiC heterostructure interface, which is an effective way to understand and design photocatalysts and electronic devices. Published under an exclusive license by AIP Publishing.