▎ 摘　　要

Graphene-based van der Waals (vdW) heterostructures have shown great potential in electronic and optoelectronic nanodevices. Herein, we investigate the electronic property and Schottky barrier of graphene/GeN3 vdW heterostructure by first-principles calculations. It is noted that the electronic natures of graphene and GeN3 monolayers are well preserved in the heterostructure lattice due to the weak vdW interaction. Interestingly, the p-type Schottky contact in graphene/GeN3 heterostructure with a barrier height of 0.21 eV can be effectively tuned by both vertical and horizontal strains. Herein, the carrier concentration in the graphene layer reaches similar to 10(13) cm(-2) level by strain engineering. It is noteworthy that the designed optoelectronic field-effect transistor based on graphene/GeN3 heterostructure exhibits distinguished responsivity of 0.297 AW(-1) and impressive external quantum efficiency of 54.5% under illumination based on further non-equilibrium Green's function simulations. Our findings are of utmost significance for the metal-semiconductor vdW contact and corresponding applications in high-performance electronic and optoelectronic devices.