Top-gate transistors fabricated on epitaxially grown molybdenum disulfide and graphene hetero-structures

We have demonstrated that by using the thermal evaporator, wafer-scale and uniform bi-layer MoS2 can be grown on graphene surfaces without introducing significant damage to the graphene channel. Compared with the top-gate transistors fabricated on standalone graphene films, the field-effect mobility value enhancement from 9.3 to 35.0 cm(2) V-1 center dot s(-1) is observed for the device fabricated on the MoS2/graphene hetero-structures, which suggests that the MoS2 layer can act as an efficient passivation layer to the graphene channel. Similar field-effect mobility values obtained for the device with only a mono-layer MoS2 passivation layer are also demonstrated.