The growth mechanism of pentacene-fullerene heteroepitaxial films

The growth of pentacene on C-60 film has been studied in real-time by low energy electron microscope. The standing-up phase overgrows on the lying-down phase at room temperature with increasing film thickness. At intermediate temperature we observed two distinct types of nucleation: an earlier nucleation of lying-down phase and a delayed nucleation of standing-up phase on the bare C-60 surface between islands of lying-down phase. Further thermal activation control enabled us to tune the types of nucleation and the standing-up phase without co-presence of the lying-down phase could be achieved above similar to 70 degrees C. (C) 2009 Elsevier B.V. All rights reserved.