▎ 摘　　要

In-plane heterojunction structures have been widely studied for its potential application on nanoelectronics devices. However, the large contact resistance caused by the unfitted interfaces hinders the application of in-plane heterostructures. Additionally, the mechanism of electron transport properties of in-plane heterostructures is also influenced by the size of materials. In this work, through using the calculations based on nonequilibrium Green's function together with density functional theory, the electron transport properties of undoped zigzag graphene-MoS2 heterostructures are explored to deeply understand the influence of size and interfaces. Significant electronic transport performances, as well as the rectifying performance and the NDR effect on these samples were obtained, which mechanisms are also discussed through analyzing the transmission spectrum at finite bias, the projected local density of states (PLDOS) and the I-V characteristics. At last, we demonstrated that the length of MoS2 dominated the profiles of transport properties of these heterojunctions, and the difference in interface would tune the output values. These interesting findings revealed the influence of length and interface of in-plane graphene-MoS2 heterojunction, which should give more guidance for further exploration and design of new nano-devices.