Tunable Electrical Contact Properties in Two-dimensional van der Waals V 2 C/MoSi 2 N 4 Heterostructures.

Two-dimensional MoSi 2 N 4 is a member of the emerging 2D MA 2 N 4 family, which has been synthesized in experiments, recently. Herein, we conduct a first-principles investigation to study more about the atomic and electronic structures of V 2 C/MoSi 2 N 4 (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 V 2 C/MoSi 2 N 4 vdWHs contact forms n-type Schottky contact with an ultralow Schottky barrier height (SBH) of 0.17eV, which is beneficial to enhance the charge injection efficiency. In addition, the electronic structure and interfacial properties of V 2 C/MoSi 2 N 4 vdWHs 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 V 2 C/MoSi 2 N 4 vdW heterostructures.