Molecular dynamics simulations of pentacene thin film growth: Stability of nuclei comprising standing molecules and their subsequent growth

Molecular dynamics (MD) simulations were applied to the study of nucleation and growth of pentacene thin films, and stability of clusters (nuclei) comprising standing molecules was investigated. In simulations, the clusters consisting of more than ten standing molecules could stably exist on hydrophobic surfaces, while several tens of molecules were necessary for stabilization on hydrophilic surfaces. Furthermore, the stabilized clusters could grow by incorporating additional molecules in MD simulations. These results suggest that nucleation occurs on hydrophobic surfaces easier than on hydrophilic surfaces and the critical size of the nuclei of "standing" pentacene is about ten molecules on hydrophobic surfaces.