In-plane anisotropy of graphene by strong interlayer interactions with van der Waals epitaxially grown MoO3

van der Waals (vdW) epitaxy can be used to grow epilayers with different symmetries on graphene, thereby imparting unprecedented properties in graphene owing to formation of anisotropic superlattices and strong interlayer interactions. Here, we report in-plane anisotropy in graphene by vdW epitaxially grown molybdenum trioxide layers with an elongated superlattice. The grown molybdenum trioxide layers led to high p-doping of the underlying graphene up top = 1.94 x 10(13 )cm(-2) regardless of the thickness of molybdenum trioxide, maintaining a high carrier mobility of 8155 cm(2) V-1 s-1. Molybdenum trioxide-induced compressive strain in graphene increased up to -0.6% with increasing molybdenum trioxide thickness. The asymmetrical band distortion of molybdenum trioxide-deposited graphene at the Fermi level led to in-plane electrical anisotropy with a high conductance ratio of 1.43 owing to the strong interlayer interaction of molybdenum trioxide-graphene. Our study presents a symmetry engineering method to induce anisotropy in symmetric two-dimensional (2D) materials via the formation of asymmetric superlattices with epitaxially grown 2D layers. License

Automated summary

Van der Waals (vdW) epitaxy is employed to grow epilayers with different symmetries on graphene, which enhances the properties of graphene through the formation of anisotropic superlattices and strong interlayer interactions. In this study, we demonstrate in-plane anisotropy in graphene by growing molybdenum trioxide layers with an elongated superlattice using vdW epitaxy. The grown molybdenum trioxide layers induce high p-doping in graphene, maintaining a high carrier mobility. The asymmetrical band distortion caused by molybdenum trioxide deposition leads to in-plane electrical anisotropy. Our findings present a method to induce anisotropy in symmetric two-dimensional materials through the formation of asymmetric superlattices.