The Comparison of Experimental and Theoretical Study on Graphene Peeling off from SiO2

Abstract

By surface scanning Raman spectrum, the peeling off state of graphene from SiO2 surface was observed. It is found because the defects of graphene produced during the transferring process, graphene are easily exfoliated. A straight upward velocity was forced on the topmost graphene, and the exfoliation process of graphene was observed when weak contacted with SiO2 substrate. In multilayer graphene system, three two critical velocities to exfoliate graphene from SiO2 surface were found, and three kinds of distinct exfoliation processes took place determined by critical upward velocities. The critical velocity to exfoliate all graphene layers was even 10 times smaller than that of topmost layer. The maximum exfoliation force to exfoliate the topmost layer graphene was 3200 times larger than that of all graphene layers. And it required 139.79 mJ/m2 to get monolayer graphene from multilayers, while peel off all layers without effort.