Boosting Carrier Mobility of Synthetic Few Layer Graphene on SiO₂ by Interlayer Rotation and Decoupling

Abstract

Abstract The role of interlayer rotation on the electrical transport of few layer graphene (FLG) is rarely considered. In this paper, the impact of twisting angle on physical and electrical properties of synthetic single crystal bilayer and few layer graphene deposited on thermal SiO 2 substrate is systematically studied. Bernal AB‐stacked graphene layers show low carrier mobility due to strong interlayer coupling and substrate scattering. A dramatic increase in carrier mobility and conductivity is observed when the graphene layers are twisted. A field effect mobility up to 15000 cm 2 V −1 s −1 and 460 nm mean free path is measured on a twisted three‐layer graphene at room temperature is among the highest for graphene transferred to SiO 2 . In average, twisted graphene shows a fivefold improvement compared to AB stacked graphene in terms of mobility and conductivity, regardless of twist angles.