In-plane gate graphene transistor with epitaxially grown molybdenum disulfide passivation layers

We demonstrate in-plane gate transistors based on the molybdenum disulfide (MoS₂)/graphene hetero-structure. The graphene works as channels while MoS₂ functions as passivation layers. The weak hysteresis of the device suggests that the MoS₂ layer can effectively passivate the graphene channel. The characteristics of devices with and without removal of MoS₂ between electrodes and graphene are also compared. The device with direct electrode/graphene contact shows a reduced contact resistance, increased drain current, and enhanced field-effect mobility. The higher field-effect mobility than that obtained through Hall measurement indicates that more carriers are present in the channel, rendering it more conductive.