Clustering feature of metal atoms in pentacene molecular solids: a first-principles study

Metal-atom contamination often induces the degradation of organic molecular devices. In this work, we studied the clustering feature of Au and Al impurity metal atoms in pentacene solids by first-principles calculations. We found that Au atoms prefer to produce clusters in a molecule-edge space due to the strong bonding among Au atoms, and such clusters can increase their sizes by producing molecule vacancies. On the other hand, the Al atom prefers to locate separately around the center of pentacene molecules due to the strong bonding between the Al atom and surrounding molecules, which produces the scattering distribution of Al atoms in pentacene solids.