Thermally-activated post-growth dewetting of fullerene $\mathrm{C_{60}}$ on mica

Understanding and controlling the growth and stability of molecular thin films on solid surfaces is necessary to develop nanomaterials with well-defined physical properties. As a prominent model system in organic electronics, we investigate the post-growth dewetting kinetics of the fullerene C$_{60}$on mica with real-time and in situ X-ray scattering. After layer-by-layer growth of C$_{60}$, we find a thermally-activated post-growth dewetting, where the smooth C$_{60}$-layer breaks up into islands. This clearly shows that growth is kinetically limited before the system moves over an activation barrier into an energetically favored configuration. From the temperature-dependent dewetting kinetics we find an effective activation barrier of 0.33 eV, which describes both the temperature-dependent macroscopic changes in the surface morphology and the microscopic processes of inter- and intralayer diffusion during dewetting