Adhesion energy characterization of monolayer graphene by vibrational spectroscopy

As at nano/micro-scale van der Waals forces often dominate various other types of forces, the accurate adhesion characterization of graphene (Gr) is essential to its processing, manipulation, and possible integration into integrated circuits and other nano/micro-scale devices. Since 2010, the reported (experimental) adhesion energy of monolayer Gr with silicon dioxide (SiO2) has increased from 151 ± 28 mJ/m2 to 450 ± 20 mJ/m2. Here, we report a set of adhesion energy values for Gr monolayers on a SiO2 substrate by adopting a unique vibrational spectroscopy approach based on the motion of adhesive microparticles on a vibrating substrate. The reported results indicate that the work-of-adhesion measurements of monolayer Gr on SiO2 could be highly scattered and its mean value is determined as WSiO2−Gr = 1160.26 mJ/m2, which is the highest value reported to date. Unlike the reported existing methods, the current non-contact and non-destructive spectral technique requires no knowledge of the mechanical properti...