▎ 摘　　要

Two-dimensional MoSi2N4 is an emerging class of 2D MA(2)N(4) family, which has recently been synthesized in experiment. Herein, we construct ultrathin van der Waals heterostructures between graphene and a new 2D Janus MoGeSiN4 material and investigate their interfacial electronic properties and tunable Schottky barriers and contact types using first-principles calculations. The GR/MoGeSiN4 vdWHs are expected to be energetically favorable and stable. The high carrier mobility in graphene/MoGeSiN4 vdWHs makes them suitable for high-speed nanoelectronic devices. Furthermore, depending on the stacking patterns, either an n-type or a p-type Schottky contact is formed at the GR/ MoGeSiN4 interface. The strain engineering and electric field can lead to the transformation from an n-type to a p-type Schottky contact or from Schottky to Ohmic contact in graphene/MoGeSiN4 heterostructure. These findings provide useful guidance for designing controllable Schottky nanodevices based on graphene/MoGeSiN4 heterostructures with high-performance.