Fig. 3
Mechanical and electrical properties of the CVD-grown AB-BLG films by interlayer epitaxy. a Typical force-displacement curves of an AB-BLG film in AFM nanoindentation. The red line is the fitting curve, and the inset is an AFM image of the suspended AB-BLG film before indentation test and the height profile (red line) along the dashed yellow line showing ~16 nm indentation in the hole. b, c Histograms of elastic stiffness (b) and breaking strength (c). Dashed lines represent Gaussian fits to the data. d Optical image (top) and illustration (bottom) of a dual-gate AB-BLG FET device. The dashed square in the optical image shows the AB-BLG channel (80 μm × 20 μm) underneath the top gate. The top-gate dielectric is 60 nm Al2O3, and the back-gate dielectric is 290 nm SiO2. e Resistance versus VBG curve measured at room temperature. f The room temperature transfer characteristics of a dual-gate AB-BLG FET. VBG is varied from −80 to 80 V with step of 10 V. g Color plot of resistance as function of both VTG and VBG obtained from the data in (f). h Resistance at Dirac point under different electrical displacement, D. i Variation of Schottky barrier height, ∆(ϕbarrier), as a function of D, inferred from the off currents at the charge neutrality point in (f). Scale bars: Inset of a 300 nm; d 20 μm
