Figure 7.

Demonstration of substrate roughness effect. (a) High-resolution LFM raw (unflatten and unfiltered; color range adjusted) image of monolayer graphene acquired at a scan size of 50 Å, a scan rate of 22.12 Hz, and a load of 3.4 nN; (b) high-resolution LFM raw (unflatten and unfiltered) image of multilayer graphene acquired at a scan size of 50 Å, a scan rate of 22.45 Hz, and a load of 2.9 nN. (a,b) were obtained using the same atomic force microscopy (AFM) probe; (c,d) comparison of cross-sectional profiles along the red (monolayer) and black (multilayer) lines in (a,b); (e) height image of graphene; (f) comparison of cross-sectional profiles along the red and black lines in (e); (g) LFM image of graphene; (h) comparison of cross-sectional profiles along the red and black lines in (g).