Ostwald ripening of PDIF-CN2 islands on exfoliated Bilayer and Multilayer graphene
J.Mathew, Gvido Bratina
University of Nova Gorica
Abstract: The layers of molecules on graphene may undergo different stages of evolution during initial stages of growth. We have studied the initial nucleation of PDIF-CN2 and the formation of molecular clusters, which move on the surface of multilayer graphene. The morphology of PDIF-CN2 was investigated by AFM as a function of time on a timescale of days. We observe a strong tendency of large PDIF-CN2 islands to attract the neighboring smaller islands through the process of ripening, leading to islands which achieved dimensions of several microns. Interestingly, the height of ripened island increased from the 1.4 nm of the original islands to 2.0 nm. This suggests that molecules in larger islands change their orientation to more upright direction relative to the substrate.