Directional Motion of a Graphene Sheet on Graded MoS2–WSe2 Lateral Heterostructures

Directional motion is one of the most fundamental motions in the nature, which is driven by specific types of gradients. The transition metal dichalcogenides graded lateral heterostructure is a valuable semiconductor playing crucial roles in electronic and optoelectronic devices. This lateral heterostructure has a graded composition and is thus a promising candidate to drive possible directional motions. Here, we perform molecular dynamics simulations to demonstrate the directional motion of a graphene sheet on top of the MoS2–WSe2 graded lateral heterostructure. It is quite interesting that the direction for the diffusion is sensitive to the graphene sheet’s initial location, which is in two different regions. The graphene sheet diffuses in opposite directions for the initial location that falls in different regions. We derive an analytic formula for the interlayer coupling potential, which discloses the underlying mechanism for the dependence of the directional motion on the initial location of the graphene sheet. These results shall be varifiable by present experimental set ups and may be valuable for the application of the transition metal dichalcogenides graded lateral heterostructure in practical electronic devices.