Tunable electrical contact properties in two-dimensional van der Waals V₂C/MoSi₂N₄ heterostructures

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.