▎ 摘　　要

Nanodevice based on MoS2 channel lateral connecting with graphene electrode was fabricated in recent experiment. In present paper, first principles calculations are carried out to reveal the relationship between contact geometries and electrical properties of graphene-MoS2 heterostructure. Four different contact edges between graphene and MoS2, namely, Armchair-Armchair, Zigzag-Armchair, Armchair-Zigzag, Zigzag-Zigzag, are investigated. Calculations indicate that MoS2 will be metalized as a consequence of junction formation with graphene. The metallic states located at Fermi level are mainly laid at the contact interface and dominated by 4d states of Mo atom as well as 2p states of both S and C atoms. Different contact geometries of graphene-MoS2 result in different charge transfer values in contact interfaces. Investigation on band alignments reveals that n-type Schottky contacts are formed in four graphene-MoS2 lateral heterostructures with barrier heights of 0.45-0.75 eV, which are larger than those of edge contact with Sc and Ti metals. The transmission gap of each configuration obtained using a two-probe system is unexpectedly larger than the intrinsic band gap of MoS2. The discrepancies of current-voltage behavior in two represented configurations demonstrate that contact geometries play an important role in electronic transport properties of graphene-MoS2 junctions. (C) 2017 Elsevier B.V. All rights reserved.