Direct CVD Growth of a Graphene/MoS2 Heterostructure with Interfacial Bonding for Two-Dimensional Electronics

This article describes a novel method for the direct synthesis of patterned graphene on transition-metal dichalcogenides (TMDs) such as molybdenum disulfide (MoS2) with chemical vapor deposition (CVD) that uses a UV/ozone-treated solid carbon source, 1,2,3,4-tetraphenylnaphthalene (TPN) as the graphene growth precursor. The UV/ozone treatment of the TPN film on the MoS2 layer improves the interfacial adhesion between the TPN and MoS2 layers. The surface-adhered TPN is directly converted to graphene on the MoS2 layer, which results in a sharp interface between graphene and MoS2. The graphene/MoS2 heterostructure with interfacial bonding yields excellent electrical and mechanical characteristics that facilitate charge injection by reducing contact resistance and improving bending stability. The excellent contact enhances the field-effect mobility of MoS2 field-effect transistors to values up to three times higher than that of the devices using source-drain electrodes prepared with the conventionally transferred CVD-grown graphene. The proposed method for the direct synthesis of graphene on TMDs is expected to have wide applications in nanoelectronics based on 2D materials.