Mechanisms of ion-beam modification of terthiophene oligomers from atomistic simulations

Ion-beam deposition on organic surfaces is a common approach to induce surface modification. Here, the difference in argon and polyatomic thiophene hyperthermal deposition on terthiophene oligomers is explored in classical molecular dynamics simulations. The forces on the atoms are determined using the second-generation reactive empirical bond order potential for hydrocarbons that is modified to include sulfur. Details of the potential fit and parametrization are provided. The simulations predict that the thiophene induces fracture of the terthiophene rings while largely retaining the chemical structure of terthiophene. Conversely, argon is predicted to alter the number of carbons within the terthiophene during modification.