Tunable electrical contact properties in two-dimensional van der Waals V₂C/MoSi₂N₄heterostructures

Two-dimensional MoSi₂N₄is a member of the emerging 2D MA₂N₄family, which has been synthesized in experiments, recently. Herein, we conduct a first-principles investigation to study more about the atomic and electronic structures of V₂C/MoSi₂N₄(1T-phase) van der Waals heterostructures (vdWHs) and interlayer distance and an external perpendicular electric field change their tunable electronic structures. We demonstrate that the V₂C/MoSi₂N₄vdWHs contact forms n-type Schottky contact with an ultralow Schottky barrier height of 0.17 eV, which is beneficial to enhance the charge injection efficiency. In addition, the electronic structure and interfacial properties of V₂C/MoSi₂N₄vdWHs can be transformed from n-type to p-type ShC through the effect of layer spacing and electric field. At the same time, the transition from ShC to OhC can also occur by relying on the electric field and different interlayer spacing. Our findings could give a novel approach for developing optoelectronic applications based on V₂C/MoSi₂N₄vdW heterostructures.