ABSTRACT
The movement of incoming molecules over a surface is controlled by the substrate-molecule and molecule-molecule interactions. In the case of a large number of molecules the mobility of the molecules deposited on the surface is impeded by the intermolecular interactions that result in the formation of clusters. Decreased surface area and increased height of islands have been noted after the Ostwald ripening. The driving force for the spontaneous process of coalescence and ripening is to lower the surface energy, which is proportional to the surface area so the Ostwald ripening is a process of growth of the crystals in a system to favor the energetic condition. The two mechanisms of Ostwald ripening are diffusion-controlled and reaction controlled growth. Ostwald ripening is one of the reasons behind the formation of 1D nanostructure from nanoparticles of metals and semiconductors. The diffusion of PDIF-CN2 molecules also depends on the density of the molecules and the molecule-molecule interaction.
