▎ 摘　　要

The high sensitivity of graphene to the surface condition of the gate dielectric layer and its poor van der Waals adhesion with a flexible substrate result in interfacial sliding and fracturing of graphene at low strains, making the successful utilization of pristine graphene (PG) in flexible electronics challenging. Here, we report a facile method for the fabrication of flexible graphene field effect transistors (F-GFETs) using sandwiched fluorinated graphene (FG). The "FG-PG-FG" sandwich structure shows a high optical transparency (> 94%) with an average carrier mobility above 340 cm(2)/V.s, higher than that obtained when GO and Ion gel were used as gate dielectric materials on F-GFETs and a relatively low gate leakage current of similar to 160 pA. Furthermore, we observed a high mechanical stability, retaining > 88% of the original current output against bending deformation of up to 6 mm and > 77% after 200 bending cycles by applying a tensile strain of 1.56%, compared to the control sample. This improved performance is attributed to the fact that the sandwiched FG provides a good dielectric environment by tuning the C/F ratio, which tightly fixes the PG under strain. These findings provide a new route for the future development of graphene-based flexible electronics.