Interfacial contact barrier and charge carrier transport of MoS 2 /metal(001) heterostructures.

The rapid rise of two-dimensional (2D) materials has aroused increasing interest in the fields of microelectronics and optoelectronics; various types of 2D van der Waals heterostructures (vdWHs), especially those based on MoS 2 , have been widely investigated in theory and experiment. However, the interfacial properties of MoS 2 and the uncommon crystal surface of traditional three-dimensional (3D) metals are yet to be explored. In this paper, we studied heterostructures composed of MoS 2 and metal(001) slabs, based on the first-principles calculations, and we uncovered that MoS 2 /Au(001) and MoS 2 /Ag(001) vdWHs reveal Schottky contacts, and MoS 2 /Cu(001) belongs to Ohmic contact and possesses ultrahigh electron tunneling probability at the equilibrium distance. Thus, the MoS 2 /Cu(001) heterostructure exhibits the best contact performance. Further investigations demonstrate that external longitudinal strain can modulate interfacial contact to engineer the Schottky-Ohmic contact transition and regulate interfacial charge transport. We believe that it is a general strategy to exploit longitudinal strain to improve interfacial contact performance to design and fabricate a multifunctional MoS 2 -based electronic device.